diff --git a/src/coreclr/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs b/src/coreclr/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
index f0b6774ac45503..01cf81f01ef424 100644
--- a/src/coreclr/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
+++ b/src/coreclr/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
@@ -61,6 +61,6 @@ public static void ApplyUpdate(Assembly assembly, ReadOnlySpan<byte> metadataDel
         /// Returns true if the apply assembly update is enabled and available.
         /// </summary>
         [FeatureSwitchDefinition("System.Reflection.Metadata.MetadataUpdater.IsSupported")]
-        public static bool IsSupported { get; } = IsApplyUpdateSupported();
+        public static bool IsSupported { get; } = !IsHotReloadDisabled && IsApplyUpdateSupported();
     }
 }
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
index fa929ccba5d438..563f2e27f7fc50 100644
--- a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
+++ b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
@@ -5,7 +5,7 @@
 
 namespace System.Reflection.Metadata
 {
-    public static class MetadataUpdater
+    public static partial class MetadataUpdater
     {
         public static void ApplyUpdate(Assembly assembly, ReadOnlySpan<byte> metadataDelta, ReadOnlySpan<byte> ilDelta, ReadOnlySpan<byte> pdbDelta)
         {
diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index 2c5f234cc2d163..16f43f682dfe8d 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -793,6 +793,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Reflection\TypeInfo.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Reflection\TypeNameResolver.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Reflection\Metadata\MetadataUpdateHandlerAttribute.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\Reflection\Metadata\MetadataUpdater.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\ResolveEventArgs.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\ResolveEventHandler.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Resources\FastResourceComparer.cs" />
diff --git a/src/libraries/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs b/src/libraries/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
new file mode 100644
index 00000000000000..585350ee3fc23a
--- /dev/null
+++ b/src/libraries/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
@@ -0,0 +1,15 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Reflection.Metadata
+{
+    public static partial class MetadataUpdater
+    {
+        /// <summary>
+        /// Returns true if hot reload is explicitly disabled via the DOTNET_HOTRELOAD_DISABLED environment variable
+        /// or the System.Reflection.Metadata.HotReloadDisabled AppContext switch set to true.
+        /// </summary>
+        internal static bool IsHotReloadDisabled =>
+            AppContextConfigHelper.GetBooleanConfig("System.Reflection.Metadata.HotReloadDisabled", "DOTNET_HOTRELOAD_DISABLED");
+    }
+}
diff --git a/src/libraries/System.Runtime.Loader/tests/ApplyUpdateTest.cs b/src/libraries/System.Runtime.Loader/tests/ApplyUpdateTest.cs
index c8576441586296..ab5388b7c5149d 100644
--- a/src/libraries/System.Runtime.Loader/tests/ApplyUpdateTest.cs
+++ b/src/libraries/System.Runtime.Loader/tests/ApplyUpdateTest.cs
@@ -6,6 +6,7 @@
 using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using Microsoft.DotNet.RemoteExecutor;
 using Xunit;
 
 namespace System.Reflection.Metadata
@@ -1157,5 +1158,20 @@ void TestIncreaseMetadataRowSize()
                 Assert.Equal("x800", pars[0].Name);
             });
         }
+
+        [ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsRemoteExecutorSupported))]
+        void TestHotReloadDisabledEnvironmentVariable()
+        {
+            // Check that DOTNET_HOTRELOAD_DISABLED=1 disables MetadataUpdater.IsSupported.
+            var options = new RemoteInvokeOptions();
+            options.StartInfo.EnvironmentVariables.Add(
+                ApplyUpdateUtil.DotNetModifiableAssembliesSwitch, ApplyUpdateUtil.DotNetModifiableAssembliesValue);
+            options.StartInfo.EnvironmentVariables.Add("DOTNET_HOTRELOAD_DISABLED", "1");
+
+            RemoteExecutor.Invoke(static () =>
+            {
+                Assert.False(MetadataUpdater.IsSupported);
+            }, options).Dispose();
+        }
     }
 }
diff --git a/src/mono/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs b/src/mono/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
index 67306e03081e28..749e1d474f2de7 100644
--- a/src/mono/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
+++ b/src/mono/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs
@@ -7,7 +7,7 @@
 
 namespace System.Reflection.Metadata
 {
-    public static class MetadataUpdater
+    public static partial class MetadataUpdater
     {
         /// <summary>
         /// Updates the specified assembly using the provided metadata, IL and PDB deltas.
@@ -51,7 +51,7 @@ public static void ApplyUpdate(Assembly assembly, ReadOnlySpan<byte> metadataDel
         internal static string GetCapabilities() => s_ApplyUpdateCapabilities.Value;
 
         [FeatureSwitchDefinition("System.Reflection.Metadata.MetadataUpdater.IsSupported")]
-        public static bool IsSupported { get; } = ApplyUpdateEnabled(justComponentCheck: 0) != 0;
+        public static bool IsSupported { get; } = !IsHotReloadDisabled && ApplyUpdateEnabled(justComponentCheck: 0) != 0;
 
         private static readonly Lazy<string> s_ApplyUpdateCapabilities = new Lazy<string>(InitializeApplyUpdateCapabilities);