diff --git a/changes.d/1973.feat.md b/changes.d/1973.feat.md
new file mode 100644
index 000000000..d6c039080
--- /dev/null
+++ b/changes.d/1973.feat.md
@@ -0,0 +1 @@
+Add a button to toggle families on and off in the tree view.
diff --git a/src/components/cylc/tree/Tree.vue b/src/components/cylc/tree/Tree.vue
index 0febfadb3..1b47f5920 100644
--- a/src/components/cylc/tree/Tree.vue
+++ b/src/components/cylc/tree/Tree.vue
@@ -25,7 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
       v-for="child of rootChildren"
       :key="child.id"
       :node="child"
-      v-bind="{ hoverable, cyclePointsOrderDesc, expandAll, filteredOutNodesCache }"
+      v-bind="{ hoverable, cyclePointsOrderDesc, expandAll, filteredOutNodesCache, flat }"
     />
   </v-container>
 </template>
@@ -82,6 +82,11 @@ export default {
       required: false,
       default: () => []
     },
+    flat: {
+      type: Boolean,
+      required: false,
+      default: true,
+    }
   },
 
   components: {
diff --git a/src/components/cylc/tree/TreeItem.vue b/src/components/cylc/tree/TreeItem.vue
index b9dd8ec4b..8a7ecad70 100644
--- a/src/components/cylc/tree/TreeItem.vue
+++ b/src/components/cylc/tree/TreeItem.vue
@@ -233,6 +233,11 @@ export default {
       type: Number,
       required: false,
     },
+    flat: {
+      type: Boolean,
+      requried: false,
+      default: false,
+    },
   },
 
   data () {
@@ -268,7 +273,7 @@ export default {
     nodeChildren () {
       return this.node.type === 'job'
         ? null
-        : getNodeChildren(this.node, this.cyclePointsOrderDesc)
+        : getNodeChildren(this.node, this.cyclePointsOrderDesc, this.flat)
     },
     nodeStyle () {
       return {
diff --git a/src/components/cylc/tree/util.js b/src/components/cylc/tree/util.js
index 3352298a7..4f5a02b5f 100644
--- a/src/components/cylc/tree/util.js
+++ b/src/components/cylc/tree/util.js
@@ -14,13 +14,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-export function getNodeChildren (node, cyclePointsOrderDesc) {
+export function getNodeChildren (node, cyclePointsOrderDesc, flat) {
   // returns child nodes folling the family tree and following sort order
   if (node.type === 'workflow' && !cyclePointsOrderDesc) {
     // a user configuration has configured the sort order for cycle points to
     // be reversed
     return [...node.children].reverse()
-  } else if (node.type === 'cycle') {
+  } else if (node.type === 'cycle' && !flat) {
     // display tasks in the inheritance tree
     if (node.familyTree?.length) {
       const rootFamily = node.familyTree[0]
diff --git a/src/views/Tree.vue b/src/views/Tree.vue
index a411713c8..d6a029c45 100644
--- a/src/views/Tree.vue
+++ b/src/views/Tree.vue
@@ -36,6 +36,20 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
           <div
             class="d-flex flex-nowrap ml-2"
           >
+            <v-btn
+              @click="flat = !flat"
+              icon
+              variant="flat"
+              size="small"
+              data-cy="toggle-families"
+            >
+              <v-icon size="x-large">
+                {{ flat? $options.icons.mdiFormatAlignRight : $options.icons.mdiFormatAlignJustify }}
+              </v-icon>
+              <v-tooltip>
+                {{ flat ? "Show Families" : "Hide Families" }}
+              </v-tooltip>
+            </v-btn>
             <v-btn
               @click="expandAll = ['workflow', 'cycle', 'family']"
               icon
@@ -72,6 +86,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
             :hoverable="false"
             :autoStripTypes="['workflow']"
             :node-filter-func="filterNode"
+            :flat="flat"
             v-bind="{ expandAll, filterState }"
             ref="treeComponent"
           />
@@ -83,7 +98,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 <script>
 import { mapState, mapGetters } from 'vuex'
-import { mdiPlus, mdiMinus } from '@mdi/js'
+import { mdiPlus, mdiMinus, mdiFormatAlignRight, mdiFormatAlignJustify } from '@mdi/js'
 import gql from 'graphql-tag'
 import graphqlMixin from '@/mixins/graphql'
 import subscriptionComponentMixin from '@/mixins/subscriptionComponent'
@@ -222,8 +237,11 @@ export default {
      */
     const tasksFilter = useInitialOptions('tasksFilter', { props, emit }, { id: null, states: null })
 
+    const flat = useInitialOptions('flat', { props, emit }, false)
+
     return {
-      tasksFilter
+      tasksFilter,
+      flat,
     }
   },
 
@@ -301,6 +319,8 @@ export default {
   icons: {
     mdiPlus,
     mdiMinus,
+    mdiFormatAlignRight,
+    mdiFormatAlignJustify,
   },
 }
 </script>
diff --git a/tests/e2e/specs/tree.cy.js b/tests/e2e/specs/tree.cy.js
index 99174a096..f84bc7410 100644
--- a/tests/e2e/specs/tree.cy.js
+++ b/tests/e2e/specs/tree.cy.js
@@ -355,4 +355,13 @@ describe('Tree view', () => {
     cy.get('[data-cy="filter task state"]')
       .contains('.v-select__selection', '(+')
   })
+
+  describe('Toggle families', () => {
+    it('Toggles between flat and hierarchical modes', () => {
+      cy.visit('/#/tree/one')
+      cy.get('.node-data-family').should('have.length', 3)
+      cy.get('[data-cy=toggle-families]').click()
+      cy.get('.node-data-family').should('have.length', 0)
+    })
+  })
 })