diff --git a/apiserver/pkg/util/cluster.go b/apiserver/pkg/util/cluster.go
index 56c32c1612..a0f45a56ba 100644
--- a/apiserver/pkg/util/cluster.go
+++ b/apiserver/pkg/util/cluster.go
@@ -223,7 +223,7 @@ func buildWorkerPodTemplate(imageVersion string, envs map[string]string, spec *a
 					Command: []string{
 						"sh",
 						"-c",
-						"until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done",
+						"until nslookup $FQ_RAY_IP; do echo waiting for K8s Service $FQ_RAY_IP; sleep 2; done",
 					},
 				},
 			},
diff --git a/helm-chart/ray-cluster/templates/raycluster-cluster.yaml b/helm-chart/ray-cluster/templates/raycluster-cluster.yaml
index 700ace391d..665560a7c2 100644
--- a/helm-chart/ray-cluster/templates/raycluster-cluster.yaml
+++ b/helm-chart/ray-cluster/templates/raycluster-cluster.yaml
@@ -97,7 +97,7 @@ spec:
         initContainers:
           - name: init
             image: {{ $values.initContainerImage | default "busybox:1.28" }}
-            command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
+            command: ['sh', '-c', "until nslookup $FQ_RAY_IP; do echo waiting for K8s Service $FQ_RAY_IP; sleep 2; done"]
             securityContext:
             {{- toYaml $values.initContainerSecurityContext | nindent 14 }}
         containers:
@@ -163,7 +163,7 @@ spec:
         initContainers:
           - name: init
             image: {{ .Values.worker.initContainerImage | default "busybox:1.28" }}
-            command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
+            command: ['sh', '-c', "until nslookup $FQ_RAY_IP; do echo waiting for K8s Service $FQ_RAY_IP; sleep 2; done"]
             securityContext:
             {{- toYaml .Values.worker.initContainerSecurityContext | nindent 14 }}
         containers:
diff --git a/ray-operator/config/samples/ray-cluster.autoscaler.large.yaml b/ray-operator/config/samples/ray-cluster.autoscaler.large.yaml
index 7df0f69312..820ddc3164 100644
--- a/ray-operator/config/samples/ray-cluster.autoscaler.large.yaml
+++ b/ray-operator/config/samples/ray-cluster.autoscaler.large.yaml
@@ -128,7 +128,7 @@ spec:
           key: value
       spec:
         initContainers:
-        # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+        # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
         - name: init
           image: busybox:1.28
           command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
diff --git a/ray-operator/config/samples/ray-cluster.autoscaler.yaml b/ray-operator/config/samples/ray-cluster.autoscaler.yaml
index dd1dc263ef..9524cdb2f3 100644
--- a/ray-operator/config/samples/ray-cluster.autoscaler.yaml
+++ b/ray-operator/config/samples/ray-cluster.autoscaler.yaml
@@ -122,7 +122,7 @@ spec:
     template:
       spec:
         initContainers:
-        # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+        # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
         - name: init
           image: busybox:1.28
           command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
diff --git a/ray-operator/config/samples/ray-cluster.complete.large.yaml b/ray-operator/config/samples/ray-cluster.complete.large.yaml
index fe6a6d3ff0..688992efdf 100644
--- a/ray-operator/config/samples/ray-cluster.complete.large.yaml
+++ b/ray-operator/config/samples/ray-cluster.complete.large.yaml
@@ -111,7 +111,7 @@ spec:
             - mountPath: /tmp/ray
               name: ray-logs
         initContainers:
-        # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+        # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
         - name: init
           image: busybox:1.28
           # Change the cluster postfix if you don't have a default setting
diff --git a/ray-operator/config/samples/ray-cluster.complete.yaml b/ray-operator/config/samples/ray-cluster.complete.yaml
index 1ff1beb8d2..f6b9588034 100644
--- a/ray-operator/config/samples/ray-cluster.complete.yaml
+++ b/ray-operator/config/samples/ray-cluster.complete.yaml
@@ -122,7 +122,7 @@ spec:
               # For production use-cases, we recommend allocating at least 8Gb memory for each Ray container.
               memory: "1G"
         initContainers:
-        # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+        # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
         - name: init
           image: busybox:1.28
           # Change the cluster postfix if you don't have a default setting
diff --git a/ray-operator/config/samples/ray-cluster.external-redis.yaml b/ray-operator/config/samples/ray-cluster.external-redis.yaml
index a9f19e47ff..936821ba15 100644
--- a/ray-operator/config/samples/ray-cluster.external-redis.yaml
+++ b/ray-operator/config/samples/ray-cluster.external-redis.yaml
@@ -124,7 +124,7 @@ spec:
       template:
         spec:
           initContainers: # to avoid worker crashing before head service is created
-            # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+            # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
             - name: init
               image: busybox:1.28
               # Change the cluster postfix if you don't have a default setting
diff --git a/ray-operator/config/samples/ray-cluster.heterogeneous.yaml b/ray-operator/config/samples/ray-cluster.heterogeneous.yaml
index 7b1047752d..c5a3bd4705 100644
--- a/ray-operator/config/samples/ray-cluster.heterogeneous.yaml
+++ b/ray-operator/config/samples/ray-cluster.heterogeneous.yaml
@@ -81,7 +81,7 @@ spec:
     template:
       spec:
         initContainers: # to avoid worker crashing before head service is created
-        # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+        # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
         - name: init
           image: busybox:1.28
           # Change the cluster postfix if you don't have a default setting
@@ -125,7 +125,7 @@ spec:
         - name: init
           image: busybox:1.28
           # Change the cluster postfix if you don't have a default setting
-          command: ['sh', '-c', "until nslookup raycluster-heterogeneous-head-svc.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
+          command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
         containers:
         - name: ray-worker # must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc'
           image: rayproject/ray:2.2.0
diff --git a/ray-operator/config/samples/ray_v1alpha1_rayjob.yaml b/ray-operator/config/samples/ray_v1alpha1_rayjob.yaml
index 0d4114228e..122c738a45 100644
--- a/ray-operator/config/samples/ray_v1alpha1_rayjob.yaml
+++ b/ray-operator/config/samples/ray_v1alpha1_rayjob.yaml
@@ -4,9 +4,9 @@ metadata:
   name: rayjob-sample
 spec:
   entrypoint: python /home/ray/samples/sample_code.py
-    # runtimeEnv decoded to '{
-    #    "pip": [
-    #        "requests==2.26.0",
+  # runtimeEnv decoded to '{
+  #    "pip": [
+  #        "requests==2.26.0",
   #        "pendulum==2.1.2"
   #    ],
   #    "env_vars": {
@@ -65,7 +65,7 @@ spec:
         template:
           spec:
             initContainers:
-              # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+              # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
               - name: init
                 image: busybox:1.28
                 command: [ 'sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done" ]
diff --git a/ray-operator/config/samples/ray_v1alpha1_rayservice.yaml b/ray-operator/config/samples/ray_v1alpha1_rayservice.yaml
index 1ed488ca3d..2b0b6c7641 100644
--- a/ray-operator/config/samples/ray_v1alpha1_rayservice.yaml
+++ b/ray-operator/config/samples/ray_v1alpha1_rayservice.yaml
@@ -89,7 +89,7 @@ spec:
         template:
           spec:
             initContainers:
-              # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+              # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
               - name: init
                 image: busybox:1.28
                 command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
diff --git a/ray-operator/config/security/ray-cluster.pod-security.yaml b/ray-operator/config/security/ray-cluster.pod-security.yaml
index fc8f776455..947c8dfe30 100644
--- a/ray-operator/config/security/ray-cluster.pod-security.yaml
+++ b/ray-operator/config/security/ray-cluster.pod-security.yaml
@@ -118,11 +118,11 @@ spec:
             seccompProfile:
               type: RuntimeDefault
         initContainers:
-        # the env var $RAY_IP is set by the operator if missing, with the value of the head service name
+        # the env var $FQ_RAY_IP is set by the operator if missing, with the value of the head service name
         - name: init-myservice
           image: busybox:1.28
           # Change the cluster postfix if you don't have a default setting
-          command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for myservice; sleep 2; done"]
+          command: ['sh', '-c', "until nslookup $RAY_IP.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $RAY_IP; sleep 2; done"]
           securityContext:
             runAsUser: 1000
             allowPrivilegeEscalation: false
diff --git a/ray-operator/controllers/ray/common/constant.go b/ray-operator/controllers/ray/common/constant.go
index 179626c52d..d7431b6b10 100644
--- a/ray-operator/controllers/ray/common/constant.go
+++ b/ray-operator/controllers/ray/common/constant.go
@@ -74,6 +74,7 @@ const (
 	NAMESPACE                               = "NAMESPACE"
 	CLUSTER_NAME                            = "CLUSTER_NAME"
 	RAY_IP                                  = "RAY_IP"
+	FQ_RAY_IP                               = "FQ_RAY_IP"
 	RAY_PORT                                = "RAY_PORT"
 	RAY_ADDRESS                             = "RAY_ADDRESS"
 	REDIS_PASSWORD                          = "REDIS_PASSWORD"
diff --git a/ray-operator/controllers/ray/common/ingress.go b/ray-operator/controllers/ray/common/ingress.go
index 32ed980d5f..1f5c7a8734 100644
--- a/ray-operator/controllers/ray/common/ingress.go
+++ b/ray-operator/controllers/ray/common/ingress.go
@@ -50,7 +50,7 @@ func BuildIngressForHeadService(cluster rayiov1alpha1.RayCluster) (*networkingv1
 			PathType: &pathType,
 			Backend: networkingv1.IngressBackend{
 				Service: &networkingv1.IngressServiceBackend{
-					Name: utils.CheckName(utils.GenerateServiceName(cluster.Name)),
+					Name: utils.GenerateServiceName(cluster.Name),
 					Port: networkingv1.ServiceBackendPort{
 						Number: dashboardPort,
 					},
diff --git a/ray-operator/controllers/ray/common/pod.go b/ray-operator/controllers/ray/common/pod.go
index 2bc0e1f271..88185a2a0f 100644
--- a/ray-operator/controllers/ray/common/pod.go
+++ b/ray-operator/controllers/ray/common/pod.go
@@ -85,7 +85,7 @@ func initTemplateAnnotations(instance rayiov1alpha1.RayCluster, podTemplate *v1.
 }
 
 // DefaultHeadPodTemplate sets the config values
-func DefaultHeadPodTemplate(instance rayiov1alpha1.RayCluster, headSpec rayiov1alpha1.HeadGroupSpec, podName string, svcName string, headPort string) v1.PodTemplateSpec {
+func DefaultHeadPodTemplate(instance rayiov1alpha1.RayCluster, headSpec rayiov1alpha1.HeadGroupSpec, podName string, headPort string) v1.PodTemplateSpec {
 	// TODO (Dmitri) The argument headPort is essentially unused;
 	// headPort is passed into setMissingRayStartParams but unused there for the head pod.
 	// To mitigate this awkwardness and reduce code redundancy, unify head and worker pod configuration logic.
@@ -100,7 +100,7 @@ func DefaultHeadPodTemplate(instance rayiov1alpha1.RayCluster, headSpec rayiov1a
 		podTemplate.Labels = make(map[string]string)
 	}
 	podTemplate.Labels = labelPod(rayiov1alpha1.HeadNode, instance.Name, "headgroup", instance.Spec.HeadGroupSpec.Template.ObjectMeta.Labels)
-	headSpec.RayStartParams = setMissingRayStartParams(headSpec.RayStartParams, rayiov1alpha1.HeadNode, svcName, headPort)
+	headSpec.RayStartParams = setMissingRayStartParams(headSpec.RayStartParams, rayiov1alpha1.HeadNode, headPort, "")
 	headSpec.RayStartParams = setAgentListPortStartParams(instance, headSpec.RayStartParams)
 
 	initTemplateAnnotations(instance, &podTemplate)
@@ -183,7 +183,7 @@ func autoscalerSupportIsStable(rayVersion string) bool {
 }
 
 // DefaultWorkerPodTemplate sets the config values
-func DefaultWorkerPodTemplate(instance rayiov1alpha1.RayCluster, workerSpec rayiov1alpha1.WorkerGroupSpec, podName string, svcName string, headPort string) v1.PodTemplateSpec {
+func DefaultWorkerPodTemplate(instance rayiov1alpha1.RayCluster, workerSpec rayiov1alpha1.WorkerGroupSpec, podName string, fqdnRayIP string, headPort string) v1.PodTemplateSpec {
 	podTemplate := workerSpec.Template
 	podTemplate.GenerateName = podName
 	if podTemplate.ObjectMeta.Namespace == "" {
@@ -198,7 +198,7 @@ func DefaultWorkerPodTemplate(instance rayiov1alpha1.RayCluster, workerSpec rayi
 		podTemplate.Labels = make(map[string]string)
 	}
 	podTemplate.Labels = labelPod(rayiov1alpha1.WorkerNode, instance.Name, workerSpec.GroupName, workerSpec.Template.ObjectMeta.Labels)
-	workerSpec.RayStartParams = setMissingRayStartParams(workerSpec.RayStartParams, rayiov1alpha1.WorkerNode, svcName, headPort)
+	workerSpec.RayStartParams = setMissingRayStartParams(workerSpec.RayStartParams, rayiov1alpha1.WorkerNode, headPort, fqdnRayIP)
 	workerSpec.RayStartParams = setAgentListPortStartParams(instance, workerSpec.RayStartParams)
 
 	initTemplateAnnotations(instance, &podTemplate)
@@ -271,7 +271,7 @@ func initReadinessProbeHandler(probe *v1.Probe, rayNodeType rayiov1alpha1.RayNod
 }
 
 // BuildPod a pod config
-func BuildPod(podTemplateSpec v1.PodTemplateSpec, rayNodeType rayiov1alpha1.RayNodeType, rayStartParams map[string]string, svcName string, headPort string, enableRayAutoscaler *bool, creator string) (aPod v1.Pod) {
+func BuildPod(podTemplateSpec v1.PodTemplateSpec, rayNodeType rayiov1alpha1.RayNodeType, rayStartParams map[string]string, headPort string, enableRayAutoscaler *bool, creator string, fqdnRayIP string) (aPod v1.Pod) {
 	pod := v1.Pod{
 		TypeMeta: metav1.TypeMeta{
 			APIVersion: "v1",
@@ -326,10 +326,10 @@ func BuildPod(podTemplateSpec v1.PodTemplateSpec, rayNodeType rayiov1alpha1.RayN
 	}
 
 	for index := range pod.Spec.InitContainers {
-		setInitContainerEnvVars(&pod.Spec.InitContainers[index], svcName)
+		setInitContainerEnvVars(&pod.Spec.InitContainers[index], fqdnRayIP)
 	}
 
-	setContainerEnvVars(&pod, rayContainerIndex, rayNodeType, rayStartParams, svcName, headPort, creator)
+	setContainerEnvVars(&pod, rayContainerIndex, rayNodeType, rayStartParams, fqdnRayIP, headPort, creator)
 
 	// health check only if FT enabled
 	if podTemplateSpec.Annotations != nil {
@@ -535,20 +535,20 @@ func labelPod(rayNodeType rayiov1alpha1.RayNodeType, rayClusterName string, grou
 	return labels
 }
 
-func setInitContainerEnvVars(container *v1.Container, svcName string) {
-	// RAY_IP can be used in the DNS lookup
+func setInitContainerEnvVars(container *v1.Container, fqdnRayIP string) {
 	if container.Env == nil || len(container.Env) == 0 {
 		container.Env = []v1.EnvVar{}
 	}
-	if !envVarExists("RAY_IP", container.Env) {
-		ip := v1.EnvVar{Name: "RAY_IP"}
-		ip.Value = svcName
-		container.Env = append(container.Env, ip)
+	if len(fqdnRayIP) != 0 { // Worker Pod
+		container.Env = append(container.Env,
+			v1.EnvVar{Name: FQ_RAY_IP, Value: fqdnRayIP},
+			// RAY_IP is deprecated and should be kept for backward compatibility purposes only.
+			v1.EnvVar{Name: RAY_IP, Value: utils.ExtractRayIPFromFQDN(fqdnRayIP)},
+		)
 	}
 }
 
-func setContainerEnvVars(pod *v1.Pod, rayContainerIndex int, rayNodeType rayiov1alpha1.RayNodeType, rayStartParams map[string]string, svcName string, headPort string, creator string) {
-	// set IP to local host if head, or the the svc otherwise  RAY_IP
+func setContainerEnvVars(pod *v1.Pod, rayContainerIndex int, rayNodeType rayiov1alpha1.RayNodeType, rayStartParams map[string]string, fqdnRayIP string, headPort string, creator string) {
 	// set the port RAY_PORT
 	// set the password?
 	container := &pod.Spec.Containers[rayContainerIndex]
@@ -556,19 +556,18 @@ func setContainerEnvVars(pod *v1.Pod, rayContainerIndex int, rayNodeType rayiov1
 		container.Env = []v1.EnvVar{}
 	}
 
-	var rayIP string
-	if rayNodeType == rayiov1alpha1.HeadNode {
-		// if head, use localhost
-		rayIP = LOCAL_HOST
-	} else {
-		// if worker, use the service name of the head
-		rayIP = svcName
+	// case 1: head   => Use LOCAL_HOST
+	// case 2: worker => Use fqdnRayIP (fully qualified domain name)
+	ip := LOCAL_HOST
+	if rayNodeType == rayiov1alpha1.WorkerNode {
+		ip = fqdnRayIP
+		container.Env = append(container.Env,
+			v1.EnvVar{Name: FQ_RAY_IP, Value: ip},
+			// RAY_IP is deprecated and should be kept for backward compatibility purposes only.
+			v1.EnvVar{Name: RAY_IP, Value: utils.ExtractRayIPFromFQDN(ip)},
+		)
 	}
 
-	if !envVarExists(RAY_IP, container.Env) {
-		ipEnv := v1.EnvVar{Name: RAY_IP, Value: rayIP}
-		container.Env = append(container.Env, ipEnv)
-	}
 	if !envVarExists(RAY_PORT, container.Env) {
 		portEnv := v1.EnvVar{Name: RAY_PORT, Value: headPort}
 		container.Env = append(container.Env, portEnv)
@@ -595,7 +594,7 @@ func setContainerEnvVars(pod *v1.Pod, rayContainerIndex int, rayNodeType rayiov1
 	// Setting the RAY_ADDRESS env allows connecting to Ray using ray.init() when connecting
 	// from within the cluster.
 	if !envVarExists(RAY_ADDRESS, container.Env) {
-		rayAddress := fmt.Sprintf("%s:%s", rayIP, headPort)
+		rayAddress := fmt.Sprintf("%s:%s", ip, headPort)
 		addressEnv := v1.EnvVar{Name: RAY_ADDRESS, Value: rayAddress}
 		container.Env = append(container.Env, addressEnv)
 	}
@@ -636,11 +635,11 @@ func envVarExists(envName string, envVars []v1.EnvVar) bool {
 }
 
 // TODO auto complete params
-func setMissingRayStartParams(rayStartParams map[string]string, nodeType rayiov1alpha1.RayNodeType, svcName string, headPort string) (completeStartParams map[string]string) {
+func setMissingRayStartParams(rayStartParams map[string]string, nodeType rayiov1alpha1.RayNodeType, headPort string, fqdnRayIP string) (completeStartParams map[string]string) {
 	// Note: The argument headPort is unused for nodeType == rayiov1alpha1.HeadNode.
 	if nodeType == rayiov1alpha1.WorkerNode {
 		if _, ok := rayStartParams["address"]; !ok {
-			address := fmt.Sprintf("%s:%s", svcName, headPort)
+			address := fmt.Sprintf("%s:%s", fqdnRayIP, headPort)
 			rayStartParams["address"] = address
 		}
 	}
diff --git a/ray-operator/controllers/ray/common/pod_test.go b/ray-operator/controllers/ray/common/pod_test.go
index 0e2ba9c2c6..6e853f521e 100644
--- a/ray-operator/controllers/ray/common/pod_test.go
+++ b/ray-operator/controllers/ray/common/pod_test.go
@@ -343,9 +343,8 @@ func TestBuildPod(t *testing.T) {
 
 	// Test head pod
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
-	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, svcName, "6379", nil, "")
+	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
+	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, "6379", nil, "", "")
 
 	// Check RAY_ADDRESS env.
 	checkPodEnv(t, pod, RAY_ADDRESS, "127.0.0.1:6379")
@@ -386,21 +385,24 @@ func TestBuildPod(t *testing.T) {
 	// testing worker pod
 	worker := cluster.Spec.WorkerGroupSpecs[0]
 	podName = cluster.Name + DashSymbol + string(rayiov1alpha1.WorkerNode) + DashSymbol + worker.GroupName + DashSymbol + utils.FormatInt32(0)
-	podTemplateSpec = DefaultWorkerPodTemplate(*cluster, worker, podName, svcName, "6379")
-	pod = BuildPod(podTemplateSpec, rayiov1alpha1.WorkerNode, worker.RayStartParams, svcName, "6379", nil, "")
+	fqdnRayIP := utils.GenerateFQDNServiceName(cluster.Name, cluster.Namespace)
+	podTemplateSpec = DefaultWorkerPodTemplate(*cluster, worker, podName, fqdnRayIP, "6379")
+	pod = BuildPod(podTemplateSpec, rayiov1alpha1.WorkerNode, worker.RayStartParams, "6379", nil, "", fqdnRayIP)
 
-	// Check RAY_ADDRESS env
-	checkPodEnv(t, pod, RAY_ADDRESS, "raycluster-sample-head-svc:6379")
+	// Check environment variables
+	checkPodEnv(t, pod, RAY_ADDRESS, "raycluster-sample-head-svc.default.svc.cluster.local:6379")
+	checkPodEnv(t, pod, FQ_RAY_IP, "raycluster-sample-head-svc.default.svc.cluster.local")
+	checkPodEnv(t, pod, RAY_IP, "raycluster-sample-head-svc")
 
 	// Check RayStartParams
-	expectedResult = fmt.Sprintf("%s:6379", svcName)
+	expectedResult = fmt.Sprintf("%s:6379", fqdnRayIP)
 	actualResult = cluster.Spec.WorkerGroupSpecs[0].RayStartParams["address"]
 
 	if !reflect.DeepEqual(expectedResult, actualResult) {
 		t.Fatalf("Expected `%v` but got `%v`", expectedResult, actualResult)
 	}
 
-	expectedCommandArg := splitAndSort("ulimit -n 65536; ray start --block --memory=1073741824 --num-cpus=1 --num-gpus=3 --address=raycluster-sample-head-svc:6379 --port=6379 --metrics-export-port=8080")
+	expectedCommandArg := splitAndSort("ulimit -n 65536; ray start --block --memory=1073741824 --num-cpus=1 --num-gpus=3 --address=raycluster-sample-head-svc.default.svc.cluster.local:6379 --port=6379 --metrics-export-port=8080")
 	actualCommandArg := splitAndSort(pod.Spec.Containers[0].Args[0])
 	if !reflect.DeepEqual(expectedCommandArg, actualCommandArg) {
 		t.Fatalf("Expected `%v` but got `%v`", expectedCommandArg, actualCommandArg)
@@ -414,9 +416,8 @@ func TestBuildPod_WithAutoscalerEnabled(t *testing.T) {
 	cluster := instance.DeepCopy()
 	cluster.Spec.EnableInTreeAutoscaling = &trueFlag
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
-	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, svcName, "6379", &trueFlag, "")
+	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
+	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, "6379", &trueFlag, "", "")
 
 	actualResult := pod.Labels[RayClusterLabelKey]
 	expectedResult := cluster.Name
@@ -470,9 +471,8 @@ func TestBuildPod_WithCreatedByRayService(t *testing.T) {
 	cluster := instance.DeepCopy()
 	cluster.Spec.EnableInTreeAutoscaling = &trueFlag
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
-	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, svcName, "6379", &trueFlag, RayServiceCreatorLabelValue)
+	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
+	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, "6379", &trueFlag, RayServiceCreatorLabelValue, "")
 
 	hasCorrectDeathEnv := false
 	for _, container := range pod.Spec.Containers {
@@ -498,7 +498,6 @@ func TestBuildPodWithAutoscalerOptions(t *testing.T) {
 	cluster := instance.DeepCopy()
 	cluster.Spec.EnableInTreeAutoscaling = &trueFlag
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
 
 	customAutoscalerImage := "custom-autoscaler-xxx"
 	customPullPolicy := v1.PullIfNotPresent
@@ -543,8 +542,8 @@ func TestBuildPodWithAutoscalerOptions(t *testing.T) {
 		EnvFrom:            customEnvFrom,
 		SecurityContext:    &customSecurityContext,
 	}
-	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
-	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, svcName, "6379", &trueFlag, "")
+	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
+	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, "6379", &trueFlag, "", "")
 	expectedContainer := *autoscalerContainer.DeepCopy()
 	expectedContainer.Image = customAutoscalerImage
 	expectedContainer.ImagePullPolicy = customPullPolicy
@@ -563,8 +562,7 @@ func TestHeadPodTemplate_WithAutoscalingEnabled(t *testing.T) {
 	cluster := instance.DeepCopy()
 	cluster.Spec.EnableInTreeAutoscaling = &trueFlag
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
+	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
 
 	// autoscaler container is injected into head pod
 	actualContainerCount := len(podTemplateSpec.Spec.Containers)
@@ -582,7 +580,7 @@ func TestHeadPodTemplate_WithAutoscalingEnabled(t *testing.T) {
 
 	// Repeat ServiceAccountName check with long cluster name.
 	cluster.Name = longString(t) // 200 chars long
-	podTemplateSpec = DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
+	podTemplateSpec = DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
 	actualResult = podTemplateSpec.Spec.ServiceAccountName
 	expectedResult = shortString(t) // 50 chars long, truncated by utils.CheckName
 	if !reflect.DeepEqual(expectedResult, actualResult) {
@@ -595,8 +593,7 @@ func TestHeadPodTemplate_WithAutoscalingEnabled(t *testing.T) {
 func TestHeadPodTemplate_WithNoServiceAccount(t *testing.T) {
 	cluster := instance.DeepCopy()
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	pod := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
+	pod := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
 
 	actualResult := pod.Spec.ServiceAccountName
 	expectedResult := ""
@@ -612,8 +609,7 @@ func TestHeadPodTemplate_WithServiceAccountNoAutoscaling(t *testing.T) {
 	serviceAccount := "head-service-account"
 	cluster.Spec.HeadGroupSpec.Template.Spec.ServiceAccountName = serviceAccount
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	pod := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
+	pod := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
 
 	actualResult := pod.Spec.ServiceAccountName
 	expectedResult := serviceAccount
@@ -630,8 +626,7 @@ func TestHeadPodTemplate_WithServiceAccount(t *testing.T) {
 	cluster.Spec.HeadGroupSpec.Template.Spec.ServiceAccountName = serviceAccount
 	cluster.Spec.EnableInTreeAutoscaling = &trueFlag
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	pod := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
+	pod := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
 
 	actualResult := pod.Spec.ServiceAccountName
 	expectedResult := serviceAccount
@@ -687,9 +682,8 @@ func TestCleanupInvalidVolumeMounts(t *testing.T) {
 
 	// Test head pod
 	podName := strings.ToLower(cluster.Name + DashSymbol + string(rayiov1alpha1.HeadNode) + DashSymbol + utils.FormatInt32(0))
-	svcName := utils.GenerateServiceName(cluster.Name)
-	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, svcName, "6379")
-	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, svcName, "6379", nil, "")
+	podTemplateSpec := DefaultHeadPodTemplate(*cluster, cluster.Spec.HeadGroupSpec, podName, "6379")
+	pod := BuildPod(podTemplateSpec, rayiov1alpha1.HeadNode, cluster.Spec.HeadGroupSpec.RayStartParams, "6379", nil, "", "")
 
 	pod.Spec.Containers[0].VolumeMounts = append(pod.Spec.Containers[0].VolumeMounts, []v1.VolumeMount{
 		{
@@ -710,14 +704,14 @@ func TestCleanupInvalidVolumeMounts(t *testing.T) {
 
 func TestDefaultWorkerPodTemplateWithName(t *testing.T) {
 	cluster := instance.DeepCopy()
-	svcName := utils.GenerateServiceName(cluster.Name)
+	fqdnRayIP := utils.GenerateFQDNServiceName(cluster.Name, cluster.Namespace)
 	worker := cluster.Spec.WorkerGroupSpecs[0]
 	worker.Template.ObjectMeta.Name = "ray-worker-test"
 	podName := cluster.Name + DashSymbol + string(rayiov1alpha1.WorkerNode) + DashSymbol + worker.GroupName + DashSymbol + utils.FormatInt32(0)
 	expectedWorker := *worker.DeepCopy()
 
 	// Pass a deep copy of worker (*worker.DeepCopy()) to prevent "worker" from updating.
-	podTemplateSpec := DefaultWorkerPodTemplate(*cluster, *worker.DeepCopy(), podName, svcName, "6379")
+	podTemplateSpec := DefaultWorkerPodTemplate(*cluster, *worker.DeepCopy(), podName, fqdnRayIP, "6379")
 	assert.Equal(t, podTemplateSpec.ObjectMeta.Name, "")
 	assert.Equal(t, worker, expectedWorker)
 }
diff --git a/ray-operator/controllers/ray/raycluster_controller.go b/ray-operator/controllers/ray/raycluster_controller.go
index 4dd74c6b5d..e3fe1d1721 100644
--- a/ray-operator/controllers/ray/raycluster_controller.go
+++ b/ray-operator/controllers/ray/raycluster_controller.go
@@ -758,15 +758,13 @@ func (r *RayClusterReconciler) createWorkerPod(instance rayiov1alpha1.RayCluster
 func (r *RayClusterReconciler) buildHeadPod(instance rayiov1alpha1.RayCluster) corev1.Pod {
 	podName := strings.ToLower(instance.Name + common.DashSymbol + string(rayiov1alpha1.HeadNode) + common.DashSymbol)
 	podName = utils.CheckName(podName) // making sure the name is valid
-	svcName := utils.GenerateServiceName(instance.Name)
-	svcName = utils.CheckName(svcName)
 	// The Ray head port used by workers to connect to the cluster (GCS server port for Ray >= 1.11.0, Redis port for older Ray.)
 	headPort := common.GetHeadPort(instance.Spec.HeadGroupSpec.RayStartParams)
 	autoscalingEnabled := instance.Spec.EnableInTreeAutoscaling
-	podConf := common.DefaultHeadPodTemplate(instance, instance.Spec.HeadGroupSpec, podName, svcName, headPort)
+	podConf := common.DefaultHeadPodTemplate(instance, instance.Spec.HeadGroupSpec, podName, headPort)
 	r.Log.Info("head pod labels", "labels", podConf.Labels)
 	creatorName := getCreator(instance)
-	pod := common.BuildPod(podConf, rayiov1alpha1.HeadNode, instance.Spec.HeadGroupSpec.RayStartParams, svcName, headPort, autoscalingEnabled, creatorName)
+	pod := common.BuildPod(podConf, rayiov1alpha1.HeadNode, instance.Spec.HeadGroupSpec.RayStartParams, headPort, autoscalingEnabled, creatorName, "")
 	// Set raycluster instance as the owner and controller
 	if err := controllerutil.SetControllerReference(&instance, &pod, r.Scheme); err != nil {
 		r.Log.Error(err, "Failed to set controller reference for raycluster pod")
@@ -791,15 +789,14 @@ func getCreator(instance rayiov1alpha1.RayCluster) string {
 // Build worker instance pods.
 func (r *RayClusterReconciler) buildWorkerPod(instance rayiov1alpha1.RayCluster, worker rayiov1alpha1.WorkerGroupSpec) corev1.Pod {
 	podName := strings.ToLower(instance.Name + common.DashSymbol + string(rayiov1alpha1.WorkerNode) + common.DashSymbol + worker.GroupName + common.DashSymbol)
-	podName = utils.CheckName(podName) // making sure the name is valid
-	svcName := utils.GenerateServiceName(instance.Name)
-	svcName = utils.CheckName(svcName)
+	podName = utils.CheckName(podName)                                            // making sure the name is valid
+	fqdnRayIP := utils.GenerateFQDNServiceName(instance.Name, instance.Namespace) // Fully Qualified Domain Name
 	// The Ray head port used by workers to connect to the cluster (GCS server port for Ray >= 1.11.0, Redis port for older Ray.)
 	headPort := common.GetHeadPort(instance.Spec.HeadGroupSpec.RayStartParams)
 	autoscalingEnabled := instance.Spec.EnableInTreeAutoscaling
-	podTemplateSpec := common.DefaultWorkerPodTemplate(instance, worker, podName, svcName, headPort)
+	podTemplateSpec := common.DefaultWorkerPodTemplate(instance, worker, podName, fqdnRayIP, headPort)
 	creatorName := getCreator(instance)
-	pod := common.BuildPod(podTemplateSpec, rayiov1alpha1.WorkerNode, worker.RayStartParams, svcName, headPort, autoscalingEnabled, creatorName)
+	pod := common.BuildPod(podTemplateSpec, rayiov1alpha1.WorkerNode, worker.RayStartParams, headPort, autoscalingEnabled, creatorName, fqdnRayIP)
 	// Set raycluster instance as the owner and controller
 	if err := controllerutil.SetControllerReference(&instance, &pod, r.Scheme); err != nil {
 		r.Log.Error(err, "Failed to set controller reference for raycluster pod")
diff --git a/ray-operator/controllers/ray/utils/dashboard_httpclient.go b/ray-operator/controllers/ray/utils/dashboard_httpclient.go
index f043c93d47..a2503d3611 100644
--- a/ray-operator/controllers/ray/utils/dashboard_httpclient.go
+++ b/ray-operator/controllers/ray/utils/dashboard_httpclient.go
@@ -130,7 +130,7 @@ func FetchDashboardAgentURL(ctx context.Context, log *logr.Logger, cli client.Cl
 
 func FetchDashboardURL(ctx context.Context, log *logr.Logger, cli client.Client, rayCluster *rayv1alpha1.RayCluster) (string, error) {
 	headSvc := &corev1.Service{}
-	headSvcName := CheckName(GenerateServiceName(rayCluster.Name))
+	headSvcName := GenerateServiceName(rayCluster.Name)
 	if err := cli.Get(ctx, client.ObjectKey{Name: headSvcName, Namespace: rayCluster.Namespace}, headSvc); err != nil {
 		return "", err
 	}
diff --git a/ray-operator/controllers/ray/utils/util.go b/ray-operator/controllers/ray/utils/util.go
index 2a2a30d15f..9e8c0e1121 100644
--- a/ray-operator/controllers/ray/utils/util.go
+++ b/ray-operator/controllers/ray/utils/util.go
@@ -118,7 +118,18 @@ func GetNamespace(metaData metav1.ObjectMeta) string {
 
 // GenerateServiceName generates a ray head service name from cluster name
 func GenerateServiceName(clusterName string) string {
-	return fmt.Sprintf("%s-%s-%s", clusterName, rayiov1alpha1.HeadNode, "svc")
+	return CheckName(fmt.Sprintf("%s-%s-%s", clusterName, rayiov1alpha1.HeadNode, "svc"))
+}
+
+// GenerateFQDNServiceName generates a Fully Qualified Domain Name.
+func GenerateFQDNServiceName(clusterName string, namespace string) string {
+	return fmt.Sprintf("%s.%s.svc.cluster.local", GenerateServiceName(clusterName), namespace)
+}
+
+// ExtractRayIPFromFQDN extracts the head service name (i.e., RAY_IP, deprecated) from a fully qualified
+// domain name (FQDN). This function is provided for backward compatibility purposes only.
+func ExtractRayIPFromFQDN(fqdnRayIP string) string {
+	return strings.Split(fqdnRayIP, ".")[0]
 }
 
 // GenerateDashboardServiceName generates a ray head service name from cluster name
diff --git a/tests/config/ray-cluster.mini.yaml.template b/tests/config/ray-cluster.mini.yaml.template
index 6f45612d53..d915145b35 100644
--- a/tests/config/ray-cluster.mini.yaml.template
+++ b/tests/config/ray-cluster.mini.yaml.template
@@ -60,7 +60,7 @@ spec:
           - name: init
             image: busybox:1.28
             # Change the cluster postfix if you don't have a default setting
-            command: ['sh', '-c', "until nslookup $$RAY_IP.$$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $$RAY_IP; sleep 2; done"]
+            command: ['sh', '-c', "until nslookup $$FQ_RAY_IP; do echo waiting for K8s Service $$FQ_RAY_IP; sleep 2; done"]
           containers:
           - name: ray-worker
             image: $ray_image
diff --git a/tests/config/ray-cluster.ray-ft.yaml.template b/tests/config/ray-cluster.ray-ft.yaml.template
index 34fd95a57a..6a7179ddf4 100644
--- a/tests/config/ray-cluster.ray-ft.yaml.template
+++ b/tests/config/ray-cluster.ray-ft.yaml.template
@@ -142,7 +142,7 @@ spec:
           initContainers: # to avoid worker crashing before head service is created
             - name: init
               image: busybox:1.28
-              command: ['sh', '-c', "until nslookup $$RAY_IP.$$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $$RAY_IP; sleep 2; done"]
+              command: ['sh', '-c', "until nslookup $$FQ_RAY_IP; do echo waiting for K8s Service $$FQ_RAY_IP; sleep 2; done"]
           containers:
             - name: ray-worker # must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc'
               image: $ray_image
diff --git a/tests/config/ray-service.yaml.template b/tests/config/ray-service.yaml.template
index 6896bc0a2e..50e21ebb50 100644
--- a/tests/config/ray-service.yaml.template
+++ b/tests/config/ray-service.yaml.template
@@ -100,7 +100,7 @@ spec:
             initContainers:
               - name: init
                 image: busybox:1.28
-                command: ['sh', '-c', "until nslookup $$RAY_IP.$$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for K8s Service $$RAY_IP; sleep 2; done"]
+                command: ['sh', '-c', "until nslookup $$FQ_RAY_IP; do echo waiting for K8s Service $$FQ_RAY_IP; sleep 2; done"]
             containers:
               - name: ray-worker
                 image: $ray_image