diff --git a/.dart_tool/package_config.json b/.dart_tool/package_config.json
index b671ff49bc5..3ecc4f840ca 100644
--- a/.dart_tool/package_config.json
+++ b/.dart_tool/package_config.json
@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2022-02-16T14:11:48.394602",
+  "generated": "2022-02-16T17:23:35.575981",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -288,12 +288,6 @@
       "packageUri": "lib/",
       "languageVersion": "2.12"
     },
-    {
-      "name": "diagnostic",
-      "rootUri": "../pkg/diagnostic",
-      "packageUri": "lib/",
-      "languageVersion": "2.0"
-    },
     {
       "name": "expect",
       "rootUri": "../pkg/expect",
diff --git a/pkg/diagnostic/CHANGELOG.md b/pkg/diagnostic/CHANGELOG.md
deleted file mode 100644
index cb12c594fc6..00000000000
--- a/pkg/diagnostic/CHANGELOG.md
+++ /dev/null
@@ -1,3 +0,0 @@
-## 0.1.0
-
-* Initial version
diff --git a/pkg/diagnostic/LICENSE b/pkg/diagnostic/LICENSE
deleted file mode 100644
index 4d1ad40a178..00000000000
--- a/pkg/diagnostic/LICENSE
+++ /dev/null
@@ -1,27 +0,0 @@
-Copyright 2018, the Dart project authors.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-    * Redistributions of source code must retain the above copyright
-      notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above
-      copyright notice, this list of conditions and the following
-      disclaimer in the documentation and/or other materials provided
-      with the distribution.
-    * Neither the name of Google LLC nor the names of its
-      contributors may be used to endorse or promote products derived
-      from this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/pkg/diagnostic/OWNERS b/pkg/diagnostic/OWNERS
deleted file mode 100644
index 2b67506d84c..00000000000
--- a/pkg/diagnostic/OWNERS
+++ /dev/null
@@ -1 +0,0 @@
-file:/tools/OWNERS_ENG
diff --git a/pkg/diagnostic/README.md b/pkg/diagnostic/README.md
deleted file mode 100644
index 4c5ddfab5c4..00000000000
--- a/pkg/diagnostic/README.md
+++ /dev/null
@@ -1,14 +0,0 @@
-# Diagnostics for Dart
-
-This package defines the support used by Dart tools to represent diagnostics, and the diagnostic codes that are shared
-by those tools.
-
-## Support
-
-Post issues and feature requests at https://github.com/dart-lang/sdk/issues
-
-## License
-
-See the [LICENSE] file.
-
-[LICENSE]: https://github.com/dart-lang/sdk/blob/main/pkg/diagnostic/LICENSE
diff --git a/pkg/diagnostic/doc/diagnostics.md b/pkg/diagnostic/doc/diagnostics.md
deleted file mode 100644
index b0261a5bde5..00000000000
--- a/pkg/diagnostic/doc/diagnostics.md
+++ /dev/null
@@ -1,4 +0,0 @@
-# Diagnostics Design
-
-This document discusses the principles used to design the diagnostics used by
-Dart tooling.
diff --git a/pkg/diagnostic/lib/diagnostic.dart b/pkg/diagnostic/lib/diagnostic.dart
deleted file mode 100644
index babf863d2bb..00000000000
--- a/pkg/diagnostic/lib/diagnostic.dart
+++ /dev/null
@@ -1,3 +0,0 @@
-// Copyright (c) 2018, the Dart project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
diff --git a/pkg/diagnostic/pubspec.yaml b/pkg/diagnostic/pubspec.yaml
deleted file mode 100644
index b42e69b0f9a..00000000000
--- a/pkg/diagnostic/pubspec.yaml
+++ /dev/null
@@ -1,8 +0,0 @@
-name: diagnostic
-# This package is not intended for consumption on pub.dev. DO NOT publish.
-publish_to: none
-author: Dart Team <misc@dartlang.org>
-description: Diagnostics for Dart
-homepage: https://github.com/dart-lang/sdk/tree/master/pkg/diagnostic
-environment:
-  sdk: '>=2.0.0-dev.48.0 <3.0.0'