diff --git a/change/@office-iss-react-native-win32-38c12dd8-daea-4309-9c21-69e05abc2891.json b/change/@office-iss-react-native-win32-38c12dd8-daea-4309-9c21-69e05abc2891.json
new file mode 100644
index 00000000000..8f54cf47d82
--- /dev/null
+++ b/change/@office-iss-react-native-win32-38c12dd8-daea-4309-9c21-69e05abc2891.json
@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Bump Jsi Version to 21",
+  "packageName": "@office-iss/react-native-win32",
+  "email": "66076509+vineethkuttan@users.noreply.github.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/react-native-platform-override-410401f9-7eb1-4e19-99d3-3fa4b5f64d11.json b/change/react-native-platform-override-410401f9-7eb1-4e19-99d3-3fa4b5f64d11.json
new file mode 100644
index 00000000000..032fa748026
--- /dev/null
+++ b/change/react-native-platform-override-410401f9-7eb1-4e19-99d3-3fa4b5f64d11.json
@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Bump Jsi Version to 21",
+  "packageName": "react-native-platform-override",
+  "email": "66076509+vineethkuttan@users.noreply.github.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/react-native-windows-1f94c94e-f7f8-4898-b6ff-ac3f5aa0a09d.json b/change/react-native-windows-1f94c94e-f7f8-4898-b6ff-ac3f5aa0a09d.json
new file mode 100644
index 00000000000..947fed0d4f7
--- /dev/null
+++ b/change/react-native-windows-1f94c94e-f7f8-4898-b6ff-ac3f5aa0a09d.json
@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Bump Jsi Version to 21",
+  "packageName": "react-native-windows",
+  "email": "66076509+vineethkuttan@users.noreply.github.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/react-native-windows-init-40fb1ee0-91c4-4972-9614-1b1ebda92bdb.json b/change/react-native-windows-init-40fb1ee0-91c4-4972-9614-1b1ebda92bdb.json
new file mode 100644
index 00000000000..acae9502d32
--- /dev/null
+++ b/change/react-native-windows-init-40fb1ee0-91c4-4972-9614-1b1ebda92bdb.json
@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Bump Jsi Version to 21",
+  "packageName": "react-native-windows-init",
+  "email": "66076509+vineethkuttan@users.noreply.github.com",
+  "dependentChangeType": "patch"
+}
diff --git a/vnext/Directory.Build.props b/vnext/Directory.Build.props
index 73a1954d191..3fa720d4148 100644
--- a/vnext/Directory.Build.props
+++ b/vnext/Directory.Build.props
@@ -34,7 +34,7 @@
     <FmtVersion>10.1.0</FmtVersion>
     <FmtCommitHash>ca2e3685b160617d3d95fcd9e789c4e06ca88</FmtCommitHash>
     <!-- Commit hash for https://github.com/microsoft/node-api-jsi code. -->
-    <NodeApiJsiCommitHash>21b47f08b762b21b1d4d970940ab23f59f43249c</NodeApiJsiCommitHash>
+    <NodeApiJsiCommitHash>4b8a4a59c4e1b7b988b809dedffd89a7662aa785</NodeApiJsiCommitHash>
   </PropertyGroup>
 
   <!--
diff --git a/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems b/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems
index a41780cf425..5b466f5cefb 100644
--- a/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems
+++ b/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems
@@ -14,7 +14,7 @@
     <!-- If your project is using glog, then GLog_IncludeDir could be set to include the actual location of glog -->
     <GLog_IncludeDir Condition="'$(GLog_IncludeDir)' == '' AND Exists('$(MSBuildThisFileDirectory)stubs\glog\logging.h')">$(MSBuildThisFileDirectory)stubs</GLog_IncludeDir>
 
-    <NodeApiJsiCommitHash>21b47f08b762b21b1d4d970940ab23f59f43249c</NodeApiJsiCommitHash>
+    <NodeApiJsiCommitHash>4b8a4a59c4e1b7b988b809dedffd89a7662aa785</NodeApiJsiCommitHash>
     <NodeApiJsiLocal Condition="Exists('$(MSBuildThisFileDirectory)NodeApiJsiRuntime.cpp')">true</NodeApiJsiLocal>
     <NodeApiJsiDir Condition="'$(NodeApiJsiDir)' == '' AND '$(NodeApiJsiLocal)' == 'true'">$(MSBuildThisFileDirectory)</NodeApiJsiDir>
     <NodeApiJsiDir Condition="'$(NodeApiJsiDir)' == '' AND '$(ReactNativeDir)' != ''">$(ReactNativeDir)\..\..\node_modules\.node-api-jsi\node-api-jsi-$(NodeApiJsiCommitHash)\</NodeApiJsiDir>
@@ -35,7 +35,7 @@
         $(NodeApiJsiSrcDir);
         %(AdditionalIncludeDirectories)
       </AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>JSI_VERSION=20;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>JSI_VERSION=21;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
     <Midl>
       <AdditionalIncludeDirectories>$(MSBuildThisFileDirectory);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
diff --git a/vnext/PropertySheets/React.Cpp.props b/vnext/PropertySheets/React.Cpp.props
index d22a035bf75..0c757c4b5a2 100644
--- a/vnext/PropertySheets/React.Cpp.props
+++ b/vnext/PropertySheets/React.Cpp.props
@@ -65,7 +65,7 @@
       <PreprocessorDefinitions Condition="'$(EnableDevServerHBCBundles)'=='true'">ENABLE_DEVSERVER_HBCBUNDLES;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <PreprocessorDefinitions Condition="'$(UseV8)'=='true'">USE_V8;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <PreprocessorDefinitions>USE_FABRIC;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <PreprocessorDefinitions>JSI_VERSION=20;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>JSI_VERSION=21;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <!--
         To address the crash on the first call to std::mutex::lock.
         See: https://github.com/microsoft/STL/wiki/Changelog#vs-2022-1710
diff --git a/vnext/ReactCommon/cgmanifest.json b/vnext/ReactCommon/cgmanifest.json
index 0a1ad2798df..386ac1607d3 100644
--- a/vnext/ReactCommon/cgmanifest.json
+++ b/vnext/ReactCommon/cgmanifest.json
@@ -6,7 +6,7 @@
                 "Type": "git",
                 "Git": {
                   "RepositoryUrl": "https://github.com/microsoft/node-api-jsi",
-                  "CommitHash": "21b47f08b762b21b1d4d970940ab23f59f43249c"
+                  "CommitHash": "4b8a4a59c4e1b7b988b809dedffd89a7662aa785"
                 }
             },
             "DevelopmentDependency": false