diff --git a/tool/grind.dart b/tool/grind.dart
index b5e735d3e..cf64cc52e 100644
--- a/tool/grind.dart
+++ b/tool/grind.dart
@@ -11,6 +11,7 @@ import 'package:grinder/grinder.dart';
 import 'package:path/path.dart' as p;
 import 'package:source_span/source_span.dart';
 
+import 'grind/bump_version.dart';
 import 'grind/generate_deprecations.dart';
 import 'grind/synchronize.dart';
 import 'grind/utils.dart';
@@ -125,6 +126,8 @@ void main(List<String> args) {
 
   pkg.addAllTasks();
 
+  addBumpVersionTasks();
+
   afterTask("pkg-npm-dev", _addDefaultExport);
   afterTask("pkg-npm-release", _addDefaultExport);
 
diff --git a/tool/grind/bump_version.dart b/tool/grind/bump_version.dart
new file mode 100644
index 000000000..a7adc5ea0
--- /dev/null
+++ b/tool/grind/bump_version.dart
@@ -0,0 +1,99 @@
+// Copyright 2024 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import 'dart:io';
+import 'dart:convert';
+
+import 'package:grinder/grinder.dart';
+import 'package:path/path.dart' as p;
+import 'package:pub_semver/pub_semver.dart';
+import 'package:source_span/source_span.dart';
+import 'package:yaml/yaml.dart';
+
+/// A regular expression that matches a version in a pubspec.
+final _pubspecVersionRegExp = RegExp(r'^version: (.*)$', multiLine: true);
+
+/// Adds grinder tasks for bumping package versions.
+void addBumpVersionTasks() {
+  for (var patch in [false, true]) {
+    for (var dev in [true, false]) {
+      addTask(GrinderTask(
+          'bump-version-${patch ? 'patch' : 'minor'}' + (dev ? '-dev' : ''),
+          taskFunction: () => _bumpVersion(patch, dev),
+          description: 'Bump the version of all packages to the next '
+              '${patch ? 'patch' : 'minor'}${dev ? ' dev' : ''} version'));
+    }
+  }
+}
+
+/// Bumps the current package versions to the next [patch] version, with `-dev`
+/// if [dev] is true.
+void _bumpVersion(bool patch, bool dev) {
+  // Returns the version to which to bump [version].
+  Version chooseNextVersion(Version version, SourceSpan span) {
+    if (dev) {
+      if (patch
+          ? version.preRelease.isNotEmpty
+          : version.patch == 0 ||
+              version.preRelease.length != 1 ||
+              version.preRelease.first != "dev") {
+        fail(span.message("Version is already pre-release", color: true));
+      }
+    } else if (version.preRelease.length == 1 &&
+        version.preRelease.first == "dev" &&
+        (patch || version.patch == 0)) {
+      // If it's already a dev version, just mark it stable instead of
+      // increasing it.
+      return Version(version.major, version.minor, version.patch);
+    }
+
+    var nextVersion =
+        patch || version.major == 0 ? version.nextPatch : version.nextMinor;
+    return Version(nextVersion.major, nextVersion.minor, nextVersion.patch,
+        pre: dev ? "dev" : null);
+  }
+
+  /// Adds a "No user-visible changes" entry for [version] to the changelog in
+  /// [dir].
+  void addChangelogEntry(String dir, Version version) {
+    var path = p.join(dir, "CHANGELOG.md");
+    var text = File(path).readAsStringSync();
+    if (!dev && text.startsWith("## ${version}-dev\n")) {
+      File(path).writeAsStringSync(
+          text.replaceFirst("## ${version}-dev\n", "## ${version}\n"));
+    } else if (text.startsWith("## ${version}\n")) {
+      return;
+    } else {
+      File(path).writeAsStringSync(
+          "## ${version}\n\n* No user-visible changes.\n\n$text");
+    }
+  }
+
+  // Bumps the current version of [pubspec] to the next [patch] version, with
+  // `-dev` if [dev] is true.
+  void bumpDartVersion(String path) {
+    var text = File(path).readAsStringSync();
+    var pubspec = loadYaml(text, sourceUrl: p.toUri(path)) as YamlMap;
+    var version = chooseNextVersion(Version.parse(pubspec["version"] as String),
+        pubspec.nodes["version"]!.span);
+    File(path).writeAsStringSync(
+        text.replaceFirst(_pubspecVersionRegExp, 'version: $version'));
+    addChangelogEntry(p.dirname(path), version);
+  }
+
+  bumpDartVersion('pubspec.yaml');
+  bumpDartVersion('pkg/sass_api/pubspec.yaml');
+
+  var packageJsonPath = 'pkg/sass-parser/package.json';
+  var packageJsonText = File(packageJsonPath).readAsStringSync();
+  var packageJson =
+      loadYaml(packageJsonText, sourceUrl: p.toUri(packageJsonPath)) as YamlMap;
+  var version = chooseNextVersion(
+      Version.parse(packageJson["version"] as String),
+      packageJson.nodes["version"]!.span);
+  File(packageJsonPath).writeAsStringSync(JsonEncoder.withIndent("  ")
+          .convert({...packageJson, "version": version.toString()}) +
+      "\n");
+  addChangelogEntry("pkg/sass-parser", version);
+}