diff --git a/src/TestFramework/TestFramework/Assertions/Assert.Contains.cs b/src/TestFramework/TestFramework/Assertions/Assert.Contains.cs
index 849d9a4bac..19d1159549 100644
--- a/src/TestFramework/TestFramework/Assertions/Assert.Contains.cs
+++ b/src/TestFramework/TestFramework/Assertions/Assert.Contains.cs
@@ -178,6 +178,14 @@ public static T ContainsSingle<T>(Func<T, bool> predicate, IEnumerable<T> collec
     public static void Contains<T>(T expected, IEnumerable<T> collection)
         => Contains(expected, collection, string.Empty, null);
 
+    /// <summary>
+    /// Tests whether the specified non-generic collection contains the given element.
+    /// </summary>
+    /// <param name="expected">The expected item.</param>
+    /// <param name="collection">The non-generic collection (like ArrayList).</param>
+    public static void Contains(object? expected, IEnumerable collection)
+        => Contains(expected, collection, string.Empty);
+
     /// <summary>
     /// Tests whether the specified collection contains the given element.
     /// </summary>
@@ -205,6 +213,31 @@ public static void Contains<T>(T expected, IEnumerable<T> collection, string? me
         }
     }
 
+    /// <summary>
+    /// Tests whether the specified collection contains the given element.
+    /// </summary>
+    /// <param name="expected">The expected item.</param>
+    /// <param name="collection">The collection.</param>
+    /// <param name="message">The message format to display when the assertion fails.</param>
+    public static void Contains(object? expected, IEnumerable collection, string? message)
+    {
+        bool isFound = false;
+        foreach (object? item in collection)
+        {
+            if (object.Equals(expected, item))
+            {
+                isFound = true;
+                break;
+            }
+        }
+
+        if (!isFound)
+        {
+            string userMessage = BuildUserMessage(message);
+            ThrowAssertContainsItemFailed(userMessage);
+        }
+    }
+
     /// <summary>
     /// Tests whether the specified collection contains the given element.
     /// </summary>
diff --git a/src/TestFramework/TestFramework/PublicAPI/PublicAPI.Unshipped.txt b/src/TestFramework/TestFramework/PublicAPI/PublicAPI.Unshipped.txt
index 7d27ebf1af..3a91f2d09b 100644
--- a/src/TestFramework/TestFramework/PublicAPI/PublicAPI.Unshipped.txt
+++ b/src/TestFramework/TestFramework/PublicAPI/PublicAPI.Unshipped.txt
@@ -1,5 +1,7 @@
 #nullable enable
 Microsoft.VisualStudio.TestTools.UnitTesting.DynamicDataSourceType.Field = 3 -> Microsoft.VisualStudio.TestTools.UnitTesting.DynamicDataSourceType
+static Microsoft.VisualStudio.TestTools.UnitTesting.Assert.Contains(object? expected, System.Collections.IEnumerable! collection) -> void
+static Microsoft.VisualStudio.TestTools.UnitTesting.Assert.Contains(object? expected, System.Collections.IEnumerable! collection, string? message) -> void
 *REMOVED*static Microsoft.VisualStudio.TestTools.UnitTesting.Assert.Instance.get -> Microsoft.VisualStudio.TestTools.UnitTesting.Assert!
 *REMOVED*static Microsoft.VisualStudio.TestTools.UnitTesting.CollectionAssert.Instance.get -> Microsoft.VisualStudio.TestTools.UnitTesting.CollectionAssert!
 *REMOVED*static Microsoft.VisualStudio.TestTools.UnitTesting.StringAssert.Instance.get -> Microsoft.VisualStudio.TestTools.UnitTesting.StringAssert!
diff --git a/test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Contains.cs b/test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Contains.cs
index b751807d44..967796f1f2 100644
--- a/test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Contains.cs
+++ b/test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Contains.cs
@@ -362,6 +362,84 @@ public void Contains_ValueExpected_ItemDoesNotExist_ThrowsException()
         action.Should().Throw<AssertFailedException>().WithMessage("*20*");
     }
 
+    /// <summary>
+    /// Tests the Contains method (value overload) when the expected item is present.
+    /// </summary>
+    public void Contains_InNonGenericCollection_ValueExpected_ItemDoesNotExist_ThrowsException()
+    {
+        // Arrange
+        var collection = new ArrayList { 5, 10, "a" };
+        object expected = 20;
+
+        // Act
+        Action action = () => Assert.Contains(expected, collection, $"Item {expected} not found");
+
+        // Assert
+        action.Should().Throw<AssertFailedException>().WithMessage($"*Item {expected} not found*");
+    }
+
+    /// <summary>
+    /// Tests the Contains method (value overload) when the expected item is present.
+    /// </summary>
+    public void Contains_InNonGenericCollection_ValueExpected_ItemExists_DoesNotThrow()
+    {
+        // Arrange
+        var collection = new ArrayList { 5, 10, "a" };
+
+        // Act
+        Action action = () => Assert.Contains("a", collection, "No failure expected");
+
+        // Assert
+        action.Should().NotThrow<AssertFailedException>();
+    }
+
+    /// <summary>
+    /// Tests the Contains method (value overload) when the expected item is present.
+    /// </summary>
+    public void Contains_InNonGenericCollection_ValueExpected_ItemExists_DoesNotThrowException()
+    {
+        // Arrange
+        var collection = new ArrayList { 5, 10, "a" };
+
+        // Act
+        Action action = () => Assert.Contains(5, collection);
+
+        // Assert
+        action.Should().NotThrow<AssertFailedException>();
+    }
+
+    /// <summary>
+    /// Tests the Contains method (value overload) when the expected item is not present.
+    /// </summary>
+    public void Contains_InNonGenericCollection_NullableValueExpected_ItemDoesNotExist_ThrowsException()
+    {
+        // Arrange
+        var collection = new ArrayList { 5, 10, "a" };
+        object? expected = null;
+
+        // Act
+        Action action = () => Assert.Contains(expected, collection, $"Item {expected} not found");
+
+        // Assert
+        action.Should().Throw<AssertFailedException>().WithMessage($"*Item {expected} not found*");
+    }
+
+    /// <summary>
+    /// Tests the Contains method (value overload) when the expected item is present.
+    /// </summary>
+    public void Contains_InNonGenericCollection_NullableValueExpected_ItemExists_DoesNotThrow()
+    {
+        // Arrange
+        var collection = new ArrayList { null, 10, "a" };
+        object? expected = null;
+
+        // Act
+        Action action = () => Assert.Contains(expected, collection, "No failure expected");
+
+        // Assert
+        action.Should().NotThrow<AssertFailedException>();
+    }
+
     /// <summary>
     /// Tests the Contains method with a comparer when the expected item is present.
     /// </summary>
@@ -882,6 +960,21 @@ public void Contains_ItemNotFound_ShowsSpecificErrorMessage()
         action.Should().Throw<AssertFailedException>().WithMessage("*Expected collection to contain the specified item*");
     }
 
+    /// <summary>
+    /// Tests that Contains (item) failure shows specific error message.
+    /// </summary>
+    public void Contains_InNonGenericCollection_ItemNotFound_ShowsSpecificErrorMessage()
+    {
+        // Arrange
+        var collection = new ArrayList { 1, 2, 3 };
+
+        // Act
+        Action action = () => Assert.Contains(5, collection);
+
+        // Assert
+        action.Should().Throw<AssertFailedException>().WithMessage("*Expected collection to contain the specified item*");
+    }
+
     /// <summary>
     /// Tests that Contains (predicate) failure shows specific error message.
     /// </summary>