diff --git a/CHANGELOG.md b/CHANGELOG.md
index b40878066960a..2bd8c11307c97 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -62,6 +62,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Return 409 Conflict HTTP status instead of 503 on failure to concurrently execute snapshots ([#8986](https://github.com/opensearch-project/OpenSearch/pull/5855))
 - Add task completion count in search backpressure stats API ([#10028](https://github.com/opensearch-project/OpenSearch/pull/10028/))
 - Performance improvement for Datetime field caching ([#4558](https://github.com/opensearch-project/OpenSearch/issues/4558))
+- Deprecate CamelCase `PathHierarchy` tokenizer name in favor to LowerCase `path_hierarchy` ([#10894](https://github.com/opensearch-project/OpenSearch/pull/10894))
 
 
 ### Deprecated
diff --git a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java
index edb8c37c2dbdd..da91238da4855 100644
--- a/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java
+++ b/modules/analysis-common/src/main/java/org/opensearch/analysis/common/CommonAnalysisModulePlugin.java
@@ -394,7 +394,21 @@ public Map<String, AnalysisProvider<TokenizerFactory>> getTokenizers() {
         // TODO deprecate and remove in API
         tokenizers.put("lowercase", XLowerCaseTokenizerFactory::new);
         tokenizers.put("path_hierarchy", PathHierarchyTokenizerFactory::new);
-        tokenizers.put("PathHierarchy", PathHierarchyTokenizerFactory::new);
+        tokenizers.put("PathHierarchy", (IndexSettings indexSettings, Environment environment, String name, Settings settings) -> {
+            if (indexSettings.getIndexVersionCreated().onOrAfter(Version.V_3_0_0)) {
+                throw new IllegalArgumentException(
+                    "The [PathHierarchy] tokenizer name was deprecated. "
+                        + "Please change the tokenizer name to [path_hierarchy] for indices created in versions 3.0 or higher instead."
+                );
+            } else {
+                deprecationLogger.deprecate(
+                    "PathHierarchy_deprecation",
+                    "The [PathHierarchy] tokenizer name is deprecated and will be removed in a future version. "
+                        + "Please change the tokenizer name to [path_hierarchy] instead."
+                );
+            }
+            return new PathHierarchyTokenizerFactory(indexSettings, environment, name, settings);
+        });
         tokenizers.put("pattern", PatternTokenizerFactory::new);
         tokenizers.put("uax_url_email", UAX29URLEmailTokenizerFactory::new);
         tokenizers.put("whitespace", WhitespaceTokenizerFactory::new);