diff --git a/change/react-native-windows-11c38437-f318-408c-8475-7a3b49e0c72f.json b/change/react-native-windows-11c38437-f318-408c-8475-7a3b49e0c72f.json
new file mode 100644
index 00000000000..73f12cb4153
--- /dev/null
+++ b/change/react-native-windows-11c38437-f318-408c-8475-7a3b49e0c72f.json
@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "Don't override Hermes platform for ARM64EC (#13490)",
+  "packageName": "react-native-windows",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/vnext/Desktop.DLL/packages.lock.json b/vnext/Desktop.DLL/packages.lock.json
index 869f5604d57..2e3f8422384 100644
--- a/vnext/Desktop.DLL/packages.lock.json
+++ b/vnext/Desktop.DLL/packages.lock.json
@@ -91,4 +91,4 @@
       }
     }
   }
-}
\ No newline at end of file
+}
diff --git a/vnext/Desktop/packages.lock.json b/vnext/Desktop/packages.lock.json
index 3684fb87a78..4cbe5db1cf4 100644
--- a/vnext/Desktop/packages.lock.json
+++ b/vnext/Desktop/packages.lock.json
@@ -64,8 +64,8 @@
       "folly": {
         "type": "Project",
         "dependencies": {
-          "Fmt": "[1.0.0, )",
-          "boost": "[1.76.0, )"
+          "boost": "[1.76.0, )",
+          "fmt": "[1.0.0, )"
         }
       },
       "follywin32": {
@@ -87,4 +87,4 @@
     "native,Version=v0.0/win-x64": {},
     "native,Version=v0.0/win-x86": {}
   }
-}
\ No newline at end of file
+}
diff --git a/vnext/PropertySheets/JSEngine.props b/vnext/PropertySheets/JSEngine.props
index 85151103924..dd69ee4e006 100644
--- a/vnext/PropertySheets/JSEngine.props
+++ b/vnext/PropertySheets/JSEngine.props
@@ -14,7 +14,7 @@
     <!-- Enabling this will (1) Include hermes glues in the Microsoft.ReactNative binaries AND (2) Make hermes the default engine -->
     <UseHermes Condition="'$(UseHermes)' == ''">true</UseHermes>
     <!-- This will be true if (1) the client want to use hermes by setting UseHermes to true OR (2) We are building for UWP where dynamic switching is enabled -->
-    <HermesVersion Condition="'$(HermesVersion)' == ''">0.1.21</HermesVersion>
+    <HermesVersion Condition="'$(HermesVersion)' == ''">0.1.23</HermesVersion>
     <HermesPackage Condition="'$(HermesPackage)' == '' And Exists('$(PkgMicrosoft_JavaScript_Hermes)')">$(PkgMicrosoft_JavaScript_Hermes)</HermesPackage>
     <HermesPackage Condition="'$(HermesPackage)' == ''">$(NuGetPackageRoot)\Microsoft.JavaScript.Hermes\$(HermesVersion)</HermesPackage>
     <EnableHermesInspectorInReleaseFlavor Condition="'$(EnableHermesInspectorInReleaseFlavor)' == ''">false</EnableHermesInspectorInReleaseFlavor>
@@ -22,7 +22,6 @@
     <HermesNoLink Condition="'$(HermesNoLink)' == '' and '$(Configuration)' == 'Release' and '$(EnableHermesInspectorInReleaseFlavor)' != 'true'">true</HermesNoLink>
     <!-- Use Hermes bytecode bundles provided by metro hermes compiler when available -->
     <EnableDevServerHBCBundles Condition="'$(EnableDevServerHBCBundles)' == ''">false</EnableDevServerHBCBundles>
-    <HermesPlatform Condition="'$(Platform)' == 'ARM64EC'">x64</HermesPlatform>
 
     <UseV8 Condition="'$(UseV8)' == ''">false</UseV8>
     <V8Version Condition="'$(V8Version)' == ''">0.71.8</V8Version>