diff --git a/src/renderer/src/lib/monaco-languages/groovy-highlighting.test.ts b/src/renderer/src/lib/monaco-languages/groovy-highlighting.test.ts
new file mode 100644
index 00000000000..7139154ecac
--- /dev/null
+++ b/src/renderer/src/lib/monaco-languages/groovy-highlighting.test.ts
@@ -0,0 +1,35 @@
+// @vitest-environment happy-dom
+import { expect, it, vi } from 'vitest'
+import { loadNodeOniguruma } from '../syntax-highlighting/oniguruma-test-harness'
+import { monaco } from '../monaco-setup'
+import { detectLanguage } from '../../../../shared/editor-language/editor-language-detect'
+
+vi.mock('../syntax-highlighting/oniguruma', () => ({ loadOniguruma: loadNodeOniguruma }))
+
+it('highlights a Jenkinsfile with token types the stock Monaco themes style', async () => {
+  const language = detectLanguage('ci/Jenkinsfile')
+  const lines = [
+    "@Library('shared') _",
+    'def count = 42 // build',
+    'sh "make ${params.TARGET}"',
+    'env.OK = count instanceof Integer'
+  ]
+  const source = lines.join('\n')
+  await monaco.editor.colorize(source, language, {})
+  const tokens = monaco.editor.tokenize(source, language)
+  const typeAt = (line: number, column: number): string | undefined =>
+    tokens[line].findLast((token) => token.offset <= column)?.type
+  const typeOf = (line: number, text: string) => typeAt(line, lines[line].indexOf(text))
+
+  expect(typeOf(0, '@Library')).toBe('annotation.groovy')
+  expect(typeOf(0, "'")).toBe('string.quoted.single.groovy')
+  expect(typeOf(1, 'def')).toBe('keyword.groovy')
+  expect(typeOf(1, '42')).toBe('number.groovy')
+  expect(typeOf(1, '//')).toBe('comment.line.double-slash.groovy')
+  expect(typeOf(2, '"')).toBe('string.quoted.double.groovy')
+  expect(typeOf(2, 'params')).toBe('source.groovy')
+  expect(typeAt(2, lines[2].length - 1)).toBe('string.quoted.double.groovy')
+  expect(typeOf(3, '.')).toBe('source.groovy')
+  expect(typeOf(3, '=')).toBe('source.groovy')
+  expect(typeOf(3, 'instanceof')).toBe('keyword.operator.instanceof.groovy')
+})
diff --git a/src/renderer/src/lib/monaco-languages/register-groovy.ts b/src/renderer/src/lib/monaco-languages/register-groovy.ts
new file mode 100644
index 00000000000..999e6fa620e
--- /dev/null
+++ b/src/renderer/src/lib/monaco-languages/register-groovy.ts
@@ -0,0 +1,71 @@
+import type * as Monaco from 'monaco-editor'
+import type { LanguageRegistration } from 'shiki/core'
+import { registerTextMateLanguage } from './textmate-language-registration'
+
+function mapGroovyTokenScope(scope: string): string | undefined {
+  if (scope.startsWith('storage.type.annotation.')) {
+    return 'annotation.groovy'
+  }
+  if (scope.startsWith('constant.numeric.')) {
+    return 'number.groovy'
+  }
+  if (scope === 'storage.type.groovy' || scope.startsWith('entity.')) {
+    return 'type.groovy'
+  }
+  if (scope.startsWith('storage.')) {
+    return 'keyword.groovy'
+  }
+  // Symbolic operators stay plain text like VS Code; only as/in/instanceof read as keywords.
+  if (
+    scope.startsWith('keyword.operator.') &&
+    !/^keyword\.operator\.(?:as|in|instanceof)\./.test(scope)
+  ) {
+    return undefined
+  }
+  return /^(?:comment|string|keyword|constant|variable|invalid)\./.test(scope) ? scope : undefined
+}
+
+// Why: stock Monaco themes style none of storage.*, and quote/comment punctuation must inherit its parent's color.
+function mapGroovyTokenScopes(scopes: readonly string[]): string {
+  // Embedded ${} code stays out of its enclosing string's color.
+  for (let index = scopes.length - 1; index >= 0 && !scopes[index].startsWith('source.'); index--) {
+    const mapped = mapGroovyTokenScope(scopes[index])
+    if (mapped) {
+      return mapped
+    }
+  }
+  return 'source.groovy'
+}
+
+async function loadGroovyTextMateGrammar(): Promise<LanguageRegistration> {
+  const { default: grammars } = await import('shiki/langs/groovy.mjs')
+  return grammars[0]
+}
+
+export function registerGroovyLanguage(monaco: Pick<typeof Monaco, 'languages'>): void {
+  registerTextMateLanguage(monaco, {
+    language: {
+      id: 'groovy',
+      extensions: ['.groovy', '.gvy', '.gy', '.gsh', '.gradle', '.jenkinsfile'],
+      filenames: ['Jenkinsfile'],
+      aliases: ['Groovy', 'groovy']
+    },
+    configuration: {
+      comments: { lineComment: '//', blockComment: ['/*', '*/'] },
+      brackets: [
+        ['{', '}'],
+        ['[', ']'],
+        ['(', ')']
+      ],
+      autoClosingPairs: [
+        { open: '{', close: '}' },
+        { open: '[', close: ']' },
+        { open: '(', close: ')' },
+        { open: '"', close: '"', notIn: ['string', 'comment'] },
+        { open: "'", close: "'", notIn: ['string', 'comment'] }
+      ]
+    },
+    loadGrammar: loadGroovyTextMateGrammar,
+    mapTokenScopes: mapGroovyTokenScopes
+  })
+}
diff --git a/src/renderer/src/lib/monaco-setup.ts b/src/renderer/src/lib/monaco-setup.ts
index 03c1d2a2dfd..afa2497cb2b 100644
--- a/src/renderer/src/lib/monaco-setup.ts
+++ b/src/renderer/src/lib/monaco-setup.ts
@@ -11,6 +11,7 @@ import tsWorker from 'monaco-editor/esm/vs/language/typescript/ts.worker?worker'
 import { registerAstroLanguage } from './monaco-languages/register-astro'
 import { registerCudaLanguage } from './monaco-languages/register-cuda'
 import { registerGlimmerLanguages } from './monaco-languages/register-glimmer'
+import { registerGroovyLanguage } from './monaco-languages/register-groovy'
 import { registerJsonlLanguage } from './monaco-languages/register-jsonl'
 import { registerLeanLanguage } from './monaco-languages/register-lean'
 import { registerMarkdownLanguage } from './monaco-languages/register-markdown'
@@ -79,6 +80,7 @@ runMonacoSetupSteps([
   ['Lean language registration', () => registerLeanLanguage(monaco)],
   ['Typst language registration', () => registerTypstLanguage(monaco)],
   ['Zig language registration', () => registerZigLanguage(monaco)],
+  ['Groovy language registration', () => registerGroovyLanguage(monaco)],
   ['JSONL language registration', () => registerJsonlLanguage(monaco)],
   ['Quarto language registration', () => registerQuartoLanguage(monaco)],
   ['Markdown language registration', () => registerMarkdownLanguage(monaco)],
diff --git a/src/shared/editor-language/editor-language-detect.test.ts b/src/shared/editor-language/editor-language-detect.test.ts
index da44f30501c..6267ba77d31 100644
--- a/src/shared/editor-language/editor-language-detect.test.ts
+++ b/src/shared/editor-language/editor-language-detect.test.ts
@@ -20,6 +20,28 @@ describe('detectLanguage', () => {
     expect(detectLanguage('C:\\app\\components\\HELLO.GTS')).toBe('glimmer-ts')
   })
 
+  it.each([
+    'src/Build.groovy',
+    'scripts/deploy.gvy',
+    'scripts/deploy.gy',
+    'scripts/shell.gsh',
+    'C:\\repo\\settings.GRADLE',
+    'Jenkinsfile',
+    'C:\\repo\\jenkinsfile',
+    'ci/Jenkinsfile.release',
+    'ci/deploy.Jenkinsfile'
+  ])('maps Groovy source %s to the groovy language id', (filePath) => {
+    expect(detectLanguage(filePath)).toBe('groovy')
+  })
+
+  it.each([
+    ['Jenkinsfile.md', 'markdown'],
+    ['build.gradle.kts', 'kotlin'],
+    ['MyJenkinsfileNotes', 'plaintext']
+  ])('keeps %s off Groovy', (filePath, language) => {
+    expect(detectLanguage(filePath)).toBe(language)
+  })
+
   it('maps Nim files to the nim language id', () => {
     expect(detectLanguage('src/main.nim')).toBe('nim')
     expect(detectLanguage('tasks/build.nims')).toBe('nim')
@@ -268,6 +290,7 @@ describe('detectLanguage', () => {
     ['#!C:\\Python\\python.exe\n', 'python'],
     ['#!/usr/bin/env python3.12', 'python'],
     ['#!/usr/bin/ruby\r\nputs 1', 'ruby'],
+    ['#!/usr/bin/env groovy\n', 'groovy'],
     ['#!/usr/bin/env awk', 'plaintext'],
     ['#!/usr/bin/env toString', 'plaintext'],
     ['#!/usr/bin/__proto__', 'plaintext'],
diff --git a/src/shared/editor-language/editor-language-detect.ts b/src/shared/editor-language/editor-language-detect.ts
index 77838f5e447..b6fcb720db7 100644
--- a/src/shared/editor-language/editor-language-detect.ts
+++ b/src/shared/editor-language/editor-language-detect.ts
@@ -91,6 +91,12 @@ const EXT_TO_LANGUAGE: Record<string, string> = {
   '.r': 'r',
   '.make': 'makefile',
   '.scala': 'scala',
+  '.groovy': 'groovy',
+  '.gvy': 'groovy',
+  '.gy': 'groovy',
+  '.gsh': 'groovy',
+  '.gradle': 'groovy',
+  '.jenkinsfile': 'groovy',
   '.dart': 'dart',
   '.ex': 'elixir',
   '.exs': 'elixir',
@@ -124,6 +130,7 @@ const EXT_TO_LANGUAGE: Record<string, string> = {
 
 const FILENAME_TO_LANGUAGE: Record<string, string> = {
   Dockerfile: 'dockerfile',
+  Jenkinsfile: 'groovy',
   Makefile: 'makefile',
   'CMakeLists.txt': 'cmake',
   '.gitignore': 'ini',
@@ -172,7 +179,8 @@ const SHEBANG_INTERPRETER_TO_LANGUAGE: Record<string, string> = {
   lua: 'lua',
   luajit: 'lua',
   pwsh: 'powershell',
-  powershell: 'powershell'
+  powershell: 'powershell',
+  groovy: 'groovy'
 }
 
 function detectShebangLanguage(content: string): string | null {
@@ -203,6 +211,8 @@ export function detectLanguage(filePath: string, content?: string): string {
   const language =
     EXT_TO_LANGUAGE[ext] ??
     detectMonacoFilenameLanguage(filename) ??
+    // Pipeline variants like Jenkinsfile.release; a known extension (Jenkinsfile.md) still wins.
+    (lowerName.startsWith('jenkinsfile.') ? 'groovy' : undefined) ??
     (lowerName === '.env' || lowerName.startsWith('.env.') ? 'ini' : 'plaintext')
   // Why: only extensionless names fall back to the shebang; unmapped extensions like .txt stay plaintext.
   if (language === 'plaintext' && ext === '' && content !== undefined) {