diff --git a/src/EditorFeatures/CSharpTest/Classification/SyntacticClassifierTests.cs b/src/EditorFeatures/CSharpTest/Classification/SyntacticClassifierTests.cs
index ddfc4449da288..aaa624648b592 100644
--- a/src/EditorFeatures/CSharpTest/Classification/SyntacticClassifierTests.cs
+++ b/src/EditorFeatures/CSharpTest/Classification/SyntacticClassifierTests.cs
@@ -1542,6 +1542,85 @@ public async Task ShebangNotAsFirstCommentInScript(TestHost testHost)
         await TestAsync(code, code, testHost, Options.Script, expected);
     }
 
+    [Theory, CombinatorialData]
+    public async Task IgnoredDirective_01(TestHost testHost)
+    {
+        await TestAsync("""
+            #:unknown // comment
+            Console.Write();
+            """,
+            testHost,
+            PPKeyword("#"),
+            PPKeyword(":"),
+            PPKeyword("unknown"),
+            String(" // comment"),
+            Identifier("Console"),
+            Operators.Dot,
+            Identifier("Write"),
+            Punctuation.OpenParen,
+            Punctuation.CloseParen,
+            Punctuation.Semicolon);
+    }
+
+    [Theory, CombinatorialData]
+    public async Task IgnoredDirective_02(TestHost testHost)
+    {
+        await TestAsync("""
+            #:sdk Test 2.1.0
+            Console.Write();
+            """,
+            testHost,
+            PPKeyword("#"),
+            PPKeyword(":"),
+            PPKeyword("sdk"),
+            String(" Test 2.1.0"),
+            Identifier("Console"),
+            Operators.Dot,
+            Identifier("Write"),
+            Punctuation.OpenParen,
+            Punctuation.CloseParen,
+            Punctuation.Semicolon);
+    }
+
+    [Theory, CombinatorialData]
+    public async Task IgnoredDirective_03(TestHost testHost)
+    {
+        await TestAsync("""
+            #:no-space
+            Console.Write();
+            """,
+            testHost,
+            PPKeyword("#"),
+            PPKeyword(":"),
+            PPKeyword("no-space"),
+            Identifier("Console"),
+            Operators.Dot,
+            Identifier("Write"),
+            Punctuation.OpenParen,
+            Punctuation.CloseParen,
+            Punctuation.Semicolon);
+    }
+
+    [Theory, CombinatorialData]
+    public async Task IgnoredDirective_04(TestHost testHost)
+    {
+        await TestAsync($"""
+            #:sdk{'\t'}Test 2.1.0
+            Console.Write();
+            """,
+            testHost,
+            PPKeyword("#"),
+            PPKeyword(":"),
+            PPKeyword("sdk"),
+            String("\tTest 2.1.0"),
+            Identifier("Console"),
+            Operators.Dot,
+            Identifier("Write"),
+            Punctuation.OpenParen,
+            Punctuation.CloseParen,
+            Punctuation.Semicolon);
+    }
+
     [Theory, CombinatorialData]
     public async Task CommentAsMethodBodyContent(TestHost testHost)
     {
diff --git a/src/EditorFeatures/TestUtilities/Classification/FormattedClassification.cs b/src/EditorFeatures/TestUtilities/Classification/FormattedClassification.cs
index 0e8032a83013e..45db1c6f8133b 100644
--- a/src/EditorFeatures/TestUtilities/Classification/FormattedClassification.cs
+++ b/src/EditorFeatures/TestUtilities/Classification/FormattedClassification.cs
@@ -202,6 +202,9 @@ public override string ToString()
             case "string - escape character":
                 return $"Escape(\"{Text}\")";
 
+            case "preprocessor keyword":
+                return $"""{nameof(FormattedClassifications.PPKeyword)}("{Text}")""";
+
             default:
                 var trimmedClassification = ClassificationName;
                 if (trimmedClassification.EndsWith(" name"))
diff --git a/src/Workspaces/CSharp/Portable/Classification/Worker.cs b/src/Workspaces/CSharp/Portable/Classification/Worker.cs
index 9603852601d07..283c9431f1a19 100644
--- a/src/Workspaces/CSharp/Portable/Classification/Worker.cs
+++ b/src/Workspaces/CSharp/Portable/Classification/Worker.cs
@@ -249,6 +249,7 @@ private void ClassifyTrivia(SyntaxTrivia trivia, SyntaxTriviaList triviaList)
             case SyntaxKind.PragmaChecksumDirectiveTrivia:
             case SyntaxKind.ReferenceDirectiveTrivia:
             case SyntaxKind.LoadDirectiveTrivia:
+            case SyntaxKind.IgnoredDirectiveTrivia:
             case SyntaxKind.NullableDirectiveTrivia:
             case SyntaxKind.BadDirectiveTrivia:
                 ClassifyPreprocessorDirective((DirectiveTriviaSyntax)trivia.GetStructure()!);
diff --git a/src/Workspaces/CSharp/Portable/Classification/Worker_Preprocesser.cs b/src/Workspaces/CSharp/Portable/Classification/Worker_Preprocesser.cs
index 6d2efd5fc182f..7ecaaf744ced3 100644
--- a/src/Workspaces/CSharp/Portable/Classification/Worker_Preprocesser.cs
+++ b/src/Workspaces/CSharp/Portable/Classification/Worker_Preprocesser.cs
@@ -4,6 +4,7 @@
 
 using Microsoft.CodeAnalysis.Classification;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.CodeAnalysis.CSharp.Classification;
 
@@ -69,6 +70,9 @@ private void ClassifyPreprocessorDirective(DirectiveTriviaSyntax node)
             case SyntaxKind.LoadDirectiveTrivia:
                 ClassifyLoadDirective((LoadDirectiveTriviaSyntax)node);
                 break;
+            case SyntaxKind.IgnoredDirectiveTrivia:
+                ClassifyIgnoredDirective((IgnoredDirectiveTriviaSyntax)node);
+                break;
             case SyntaxKind.NullableDirectiveTrivia:
                 ClassifyNullableDirective((NullableDirectiveTriviaSyntax)node);
                 break;
@@ -324,6 +328,29 @@ private void ClassifyLoadDirective(LoadDirectiveTriviaSyntax node)
         ClassifyDirectiveTrivia(node);
     }
 
+    private void ClassifyIgnoredDirective(IgnoredDirectiveTriviaSyntax node)
+    {
+        AddClassification(node.HashToken, ClassificationTypeNames.PreprocessorKeyword);
+        AddClassification(node.ColonToken, ClassificationTypeNames.PreprocessorKeyword);
+
+        // The first part (separated by whitespace) of content is a "keyword", e.g., 'sdk' in '#:sdk Test'.
+        // We only recognize some whitespace characters here for simplicity and performance.
+        if (node.Content.Text.IndexOfAny([' ', '\t']) is > 0 and var firstSpaceIndex)
+        {
+            var keywordSpan = new TextSpan(node.Content.SpanStart, firstSpaceIndex);
+            var stringLiteralSpan = TextSpan.FromBounds(node.Content.SpanStart + firstSpaceIndex, node.Content.FullSpan.End);
+
+            AddClassification(keywordSpan, ClassificationTypeNames.PreprocessorKeyword);
+            AddClassification(stringLiteralSpan, ClassificationTypeNames.StringLiteral);
+        }
+        else
+        {
+            AddClassification(node.Content, ClassificationTypeNames.PreprocessorKeyword);
+        }
+
+        ClassifyDirectiveTrivia(node);
+    }
+
     private void ClassifyNullableDirective(NullableDirectiveTriviaSyntax node)
     {
         AddClassification(node.HashToken, ClassificationTypeNames.PreprocessorKeyword);