diff --git a/packages/tailwindcss-language-server/src/config.ts b/packages/tailwindcss-language-server/src/config.ts
index 90fb3207..fd3a9b76 100644
--- a/packages/tailwindcss-language-server/src/config.ts
+++ b/packages/tailwindcss-language-server/src/config.ts
@@ -22,6 +22,7 @@ function getDefaultSettings(): Settings {
       rootFontSize: 16,
       lint: {
         cssConflict: 'warning',
+        deprecatedClass: 'warning',
         invalidApply: 'error',
         invalidScreen: 'error',
         invalidVariant: 'error',
diff --git a/packages/tailwindcss-language-service/src/codeActions/codeActionProvider.ts b/packages/tailwindcss-language-service/src/codeActions/codeActionProvider.ts
index 7ebf79cb..f7b55e70 100644
--- a/packages/tailwindcss-language-service/src/codeActions/codeActionProvider.ts
+++ b/packages/tailwindcss-language-service/src/codeActions/codeActionProvider.ts
@@ -13,6 +13,7 @@ import {
   isInvalidScreenDiagnostic,
   isInvalidVariantDiagnostic,
   isRecommendedVariantOrderDiagnostic,
+  isDeprecatedClassDiagnostic,
 } from '../diagnostics/types'
 import { flatten, dedupeBy } from '../util/array'
 import { provideCssConflictCodeActions } from './provideCssConflictCodeActions'
@@ -74,7 +75,8 @@ export async function doCodeActions(
         isInvalidTailwindDirectiveDiagnostic(diagnostic) ||
         isInvalidScreenDiagnostic(diagnostic) ||
         isInvalidVariantDiagnostic(diagnostic) ||
-        isRecommendedVariantOrderDiagnostic(diagnostic)
+        isRecommendedVariantOrderDiagnostic(diagnostic) ||
+        isDeprecatedClassDiagnostic(diagnostic)
       ) {
         return provideSuggestionCodeActions(state, params, diagnostic)
       }
diff --git a/packages/tailwindcss-language-service/src/codeActions/provideSuggestionCodeActions.ts b/packages/tailwindcss-language-service/src/codeActions/provideSuggestionCodeActions.ts
index a0201699..c8aedde3 100644
--- a/packages/tailwindcss-language-service/src/codeActions/provideSuggestionCodeActions.ts
+++ b/packages/tailwindcss-language-service/src/codeActions/provideSuggestionCodeActions.ts
@@ -1,6 +1,7 @@
 import type { State } from '../util/state'
 import type { CodeActionParams, CodeAction } from 'vscode-languageserver'
 import type {
+  DeprecatedClassDiagnostic,
   InvalidConfigPathDiagnostic,
   InvalidTailwindDirectiveDiagnostic,
   InvalidScreenDiagnostic,
@@ -12,6 +13,7 @@ export function provideSuggestionCodeActions(
   _state: State,
   params: CodeActionParams,
   diagnostic:
+    | DeprecatedClassDiagnostic
     | InvalidConfigPathDiagnostic
     | InvalidTailwindDirectiveDiagnostic
     | InvalidScreenDiagnostic
diff --git a/packages/tailwindcss-language-service/src/diagnostics/diagnosticsProvider.ts b/packages/tailwindcss-language-service/src/diagnostics/diagnosticsProvider.ts
index 18994526..4c7d0eb0 100644
--- a/packages/tailwindcss-language-service/src/diagnostics/diagnosticsProvider.ts
+++ b/packages/tailwindcss-language-service/src/diagnostics/diagnosticsProvider.ts
@@ -9,11 +9,13 @@ import { getInvalidConfigPathDiagnostics } from './getInvalidConfigPathDiagnosti
 import { getInvalidTailwindDirectiveDiagnostics } from './getInvalidTailwindDirectiveDiagnostics'
 import { getRecommendedVariantOrderDiagnostics } from './getRecommendedVariantOrderDiagnostics'
 import { getInvalidSourceDiagnostics } from './getInvalidSourceDiagnostics'
+import { getDeprecatedClassDiagnostics } from './getDeprecatedClassDiagnostics'
 
 export async function doValidate(
   state: State,
   document: TextDocument,
   only: DiagnosticKind[] = [
+    DiagnosticKind.Deprecation,
     DiagnosticKind.CssConflict,
     DiagnosticKind.InvalidApply,
     DiagnosticKind.InvalidScreen,
@@ -28,6 +30,9 @@ export async function doValidate(
 
   return settings.tailwindCSS.validate
     ? [
+        ...(only.includes(DiagnosticKind.Deprecation)
+          ? await getDeprecatedClassDiagnostics(state, document, settings)
+          : []),
         ...(only.includes(DiagnosticKind.CssConflict)
           ? await getCssConflictDiagnostics(state, document, settings)
           : []),
diff --git a/packages/tailwindcss-language-service/src/diagnostics/getDeprecatedClassDiagnostics.ts b/packages/tailwindcss-language-service/src/diagnostics/getDeprecatedClassDiagnostics.ts
new file mode 100644
index 00000000..d753641e
--- /dev/null
+++ b/packages/tailwindcss-language-service/src/diagnostics/getDeprecatedClassDiagnostics.ts
@@ -0,0 +1,62 @@
+import type { State, Settings } from '../util/state'
+import { type DeprecatedClassDiagnostic, DiagnosticKind } from './types'
+import { findClassListsInDocument, getClassNamesInClassList } from '../util/find'
+import type { TextDocument } from 'vscode-languageserver-textdocument'
+
+export async function getDeprecatedClassDiagnostics(
+  state: State,
+  document: TextDocument,
+  settings: Settings,
+): Promise<DeprecatedClassDiagnostic[]> {
+  // Only v4 projects can report deprecations
+  if (!state.v4) return []
+
+  // This is an earlier v4 version that does not support class deprecations
+  if (!state.designSystem.classMetadata) return []
+
+  let severity = settings.tailwindCSS.lint.deprecatedClass
+  if (severity === 'ignore') return []
+
+  // Fill in the list of statically known deprecated classes
+  let deprecations = new Map<string, boolean>(
+    state.classList.map(([className, meta]) => [className, meta.deprecated ?? false]),
+  )
+
+  function isDeprecated(className: string) {
+    if (deprecations.has(className)) {
+      return deprecations.get(className)
+    }
+
+    let metadata = state.designSystem.classMetadata([className])[0]
+    let deprecated = metadata?.deprecated ?? false
+
+    deprecations.set(className, deprecated)
+
+    return deprecated
+  }
+
+  let diagnostics: DeprecatedClassDiagnostic[] = []
+  let classLists = await findClassListsInDocument(state, document)
+
+  for (let classList of classLists) {
+    let classNames = getClassNamesInClassList(classList, state.blocklist)
+
+    for (let className of classNames) {
+      if (!isDeprecated(className.className)) continue
+
+      diagnostics.push({
+        code: DiagnosticKind.DeprecatedClass,
+        className,
+        range: className.range,
+        severity:
+          severity === 'error'
+            ? 1 /* DiagnosticSeverity.Error */
+            : 2 /* DiagnosticSeverity.Warning */,
+        message: `'${className.className}' is deprecated.`,
+        suggestions: [],
+      })
+    }
+  }
+
+  return diagnostics
+}
diff --git a/packages/tailwindcss-language-service/src/diagnostics/types.ts b/packages/tailwindcss-language-service/src/diagnostics/types.ts
index 7cb68a7e..640ca0ff 100644
--- a/packages/tailwindcss-language-service/src/diagnostics/types.ts
+++ b/packages/tailwindcss-language-service/src/diagnostics/types.ts
@@ -6,12 +6,25 @@ export enum DiagnosticKind {
   InvalidApply = 'invalidApply',
   InvalidScreen = 'invalidScreen',
   InvalidVariant = 'invalidVariant',
+  DeprecatedClass = 'deprecatedClass',
   InvalidConfigPath = 'invalidConfigPath',
   InvalidTailwindDirective = 'invalidTailwindDirective',
   InvalidSourceDirective = 'invalidSourceDirective',
   RecommendedVariantOrder = 'recommendedVariantOrder',
 }
 
+export type DeprecatedClassDiagnostic = Diagnostic & {
+  code: DiagnosticKind.DeprecatedClass
+  className: DocumentClassName
+  suggestions: string[]
+}
+
+export function isDeprecatedClassDiagnostic(
+  diagnostic: AugmentedDiagnostic,
+): diagnostic is DeprecatedClassDiagnostic {
+  return diagnostic.code === DiagnosticKind.DeprecatedClass
+}
+
 export type CssConflictDiagnostic = Diagnostic & {
   code: DiagnosticKind.CssConflict
   className: DocumentClassName
@@ -101,6 +114,7 @@ export function isRecommendedVariantOrderDiagnostic(
 }
 
 export type AugmentedDiagnostic =
+  | DeprecatedClassDiagnostic
   | CssConflictDiagnostic
   | InvalidApplyDiagnostic
   | InvalidScreenDiagnostic
diff --git a/packages/tailwindcss-language-service/src/util/state.ts b/packages/tailwindcss-language-service/src/util/state.ts
index 621add49..b20727fc 100644
--- a/packages/tailwindcss-language-service/src/util/state.ts
+++ b/packages/tailwindcss-language-service/src/util/state.ts
@@ -54,6 +54,7 @@ export type TailwindCssSettings = {
   colorDecorators: boolean
   lint: {
     cssConflict: DiagnosticSeveritySetting
+    deprecatedClass: DiagnosticSeveritySetting
     invalidApply: DiagnosticSeveritySetting
     invalidScreen: DiagnosticSeveritySetting
     invalidVariant: DiagnosticSeveritySetting
@@ -92,6 +93,7 @@ export interface Variant {
 export interface ClassMetadata {
   color: culori.Color | KeywordColor | null
   modifiers?: string[]
+  deprecated?: boolean
 }
 
 export type ClassEntry = [string, ClassMetadata]
diff --git a/packages/tailwindcss-language-service/src/util/v4/design-system.ts b/packages/tailwindcss-language-service/src/util/v4/design-system.ts
index cce64d4b..b6a86cfb 100644
--- a/packages/tailwindcss-language-service/src/util/v4/design-system.ts
+++ b/packages/tailwindcss-language-service/src/util/v4/design-system.ts
@@ -10,6 +10,15 @@ export interface Theme {
 
 export interface ClassMetadata {
   modifiers: string[]
+  deprecated?: boolean
+}
+
+export interface VariantMetadata {
+  deprecated?: boolean
+}
+
+export interface ThemeMetadata {
+  deprecated?: boolean
 }
 
 export type ClassEntry = [string, ClassMetadata]
@@ -40,6 +49,9 @@ export interface DesignSystem {
 
   // Optional because it did not exist in earlier v4 alpha versions
   resolveThemeValue?(path: string): string | undefined
+  classMetadata?(classes: string[]): (ClassMetadata | null)[]
+  variantMetadata?(variants: string[]): (VariantMetadata | null)[]
+  themeMetadata?(keys: string[]): (ThemeMetadata | null)[]
 }
 
 export interface DesignSystem {
diff --git a/packages/vscode-tailwindcss/CHANGELOG.md b/packages/vscode-tailwindcss/CHANGELOG.md
index 8896fc88..82548174 100644
--- a/packages/vscode-tailwindcss/CHANGELOG.md
+++ b/packages/vscode-tailwindcss/CHANGELOG.md
@@ -7,6 +7,7 @@
 - Show source diagnostics when imports contain a layer ([#1204](https://github.com/tailwindlabs/tailwindcss-intellisense/pull/1204))
 - Only detect project roots in v4 when using certain CSS features ([#1205](https://github.com/tailwindlabs/tailwindcss-intellisense/pull/1205))
 - Update Tailwind CSS v4 version to v4.0.6 ([#1207](https://github.com/tailwindlabs/tailwindcss-intellisense/pull/1207))
+- Add support for detecting deprecated classes ([#1084](https://github.com/tailwindlabs/tailwindcss-intellisense/pull/1084))
 
 ## 0.14.4
 
diff --git a/packages/vscode-tailwindcss/README.md b/packages/vscode-tailwindcss/README.md
index 62165308..2befb4f5 100644
--- a/packages/vscode-tailwindcss/README.md
+++ b/packages/vscode-tailwindcss/README.md
@@ -148,6 +148,10 @@ Unknown or invalid path used with the [`theme` helper](https://tailwindcss.com/d
 
 Class names on the same HTML element which apply the same CSS property or properties. **Default: `warning`**
 
+#### `tailwindCSS.lint.deprecatedClass`
+
+Use of a deprecated class. **Default: `warning`**
+
 #### `tailwindCSS.lint.recommendedVariantOrder`
 
 Class variants not in the recommended order (applies in [JIT mode](https://tailwindcss.com/docs/just-in-time-mode) only). **Default: `warning`**
diff --git a/packages/vscode-tailwindcss/package.json b/packages/vscode-tailwindcss/package.json
index 52ad3ebd..9b4ec038 100644
--- a/packages/vscode-tailwindcss/package.json
+++ b/packages/vscode-tailwindcss/package.json
@@ -225,6 +225,17 @@
           "markdownDescription": "Class names on the same HTML element which apply the same CSS property or properties",
           "scope": "language-overridable"
         },
+        "tailwindCSS.lint.deprecatedClass": {
+          "type": "string",
+          "enum": [
+            "ignore",
+            "warning",
+            "error"
+          ],
+          "default": "warning",
+          "markdownDescription": "Use of a deprecated utility class",
+          "scope": "language-overridable"
+        },
         "tailwindCSS.lint.invalidApply": {
           "type": "string",
           "enum": [