diff --git a/src/main/git/worktree-include-file.test.ts b/src/main/git/worktree-include-file.test.ts
index a128d12a41d..c01a6c01b12 100644
--- a/src/main/git/worktree-include-file.test.ts
+++ b/src/main/git/worktree-include-file.test.ts
@@ -8,7 +8,10 @@ import {
   getWorktreeIncludeGlobStepCount,
   matchesWorktreeIncludeGlob
 } from './worktree-include-glob'
-import { parseWorktreeIncludePatterns } from './worktree-include-pattern'
+import {
+  isIncludedByWorktreePatterns,
+  parseWorktreeIncludePatterns
+} from './worktree-include-pattern'
 import { gitExecFileAsync } from './runner'
 
 vi.mock('./runner', () => ({
@@ -23,8 +26,15 @@ function mockGit(options: {
   collapsedEntries?: string[]
   targetedEntries?: string[]
   ignored?: string[]
+  ignoreCase?: boolean
 }): void {
   gitExecFileAsyncMock.mockImplementation(async (args, execOptions) => {
+    if (args.includes('config')) {
+      if (options.ignoreCase === undefined) {
+        throw Object.assign(new Error('unset'), { code: 1 })
+      }
+      return { stdout: `${options.ignoreCase}\n`, stderr: '' }
+    }
     if (args.includes('ls-files')) {
       const entries = args.includes('--directory')
         ? (options.collapsedEntries ?? options.entries ?? [])
@@ -79,6 +89,24 @@ describe('parseWorktreeIncludePatterns', () => {
     expect(glob.glob && matchesWorktreeIncludeGlob(glob.glob, longNonMatch)).toBe(false)
   })
 
+  it('matches literals and globs case-insensitively when the repository requires it', () => {
+    const literal = parseWorktreeIncludePatterns('.env\n')
+    const glob = parseWorktreeIncludePatterns('config/**/secret.json\n')
+
+    expect(isIncludedByWorktreePatterns(literal, '.ENV', false, { remaining: 100 }, true)).toBe(
+      true
+    )
+    expect(
+      isIncludedByWorktreePatterns(
+        glob,
+        'CONFIG/LOCAL/SECRET.JSON',
+        false,
+        { remaining: 1_000 },
+        true
+      )
+    ).toBe(true)
+  })
+
   it('charges variable-width regex backtracking against the literal suffix', () => {
     const glob = compileWorktreeIncludeGlob(`*${'a'.repeat(1_000)}`)
 
@@ -86,6 +114,14 @@ describe('parseWorktreeIncludePatterns', () => {
     expect(getWorktreeIncludeGlobStepCount(compileWorktreeIncludeGlob('prefix*'), 'short')).toBe(12)
   })
 
+  it('charges directory-only rules that reject a root file before glob evaluation', () => {
+    const patterns = parseWorktreeIncludePatterns('dir-*/\n')
+
+    expect(() =>
+      isIncludedByWorktreePatterns(patterns, 'root-file', false, { remaining: 1 })
+    ).toThrow('matching exceeded its CPU budget')
+  })
+
   it('rejects pathological pattern counts before worktree creation can fan out', () => {
     expect(() => parseWorktreeIncludePatterns(`${'.env\n'.repeat(4_097)}`)).toThrow(
       'contains too many patterns'
@@ -153,7 +189,7 @@ describe('resolveWorktreeIncludePaths', () => {
       'cache'
     ])
 
-    expect(gitExecFileAsyncMock).toHaveBeenCalledTimes(3)
+    expect(gitExecFileAsyncMock).toHaveBeenCalledTimes(4)
     expect(
       gitExecFileAsyncMock.mock.calls.every(([, options]) => options.wslDistro === 'Ubuntu')
     ).toBe(true)
@@ -213,6 +249,22 @@ describe('resolveWorktreeIncludePaths', () => {
     ])
   })
 
+  it('uses Git case-folding for collapsed and targeted matches', async () => {
+    writeInclude('.env\n')
+    mockGit({
+      collapsedEntries: ['.ENV'],
+      targetedEntries: ['parent/.ENV'],
+      ignored: ['.ENV', 'parent/.ENV'],
+      ignoreCase: true
+    })
+
+    await expect(resolveWorktreeIncludePaths(repo)).resolves.toEqual(['.ENV', 'parent/.ENV'])
+    const targetedArgs = gitExecFileAsyncMock.mock.calls.find(
+      ([args]) => args.includes('ls-files') && !args.includes('--directory')
+    )?.[0]
+    expect(targetedArgs).toContain(':(icase,glob)**/.env')
+  })
+
   it('honors dir-only patterns against directory entries', async () => {
     writeInclude('logs/\n')
     writeFileSync(join(repo, 'logs'), 'not a dir')
diff --git a/src/main/git/worktree-include-file.ts b/src/main/git/worktree-include-file.ts
index 0e356d9d5af..b1138f7a749 100644
--- a/src/main/git/worktree-include-file.ts
+++ b/src/main/git/worktree-include-file.ts
@@ -4,6 +4,7 @@ import { checkIgnoredPaths } from './check-ignored-paths'
 import type { GitRuntimeOptions } from './git-runtime-options'
 import {
   chunkWorktreeIncludePathspecs,
+  getWorktreeIncludeIgnoreCase,
   listGitignoredEntries,
   worktreeIncludePatternToGitDescendantPathspec,
   worktreeIncludePatternToGitPathspec,
@@ -113,6 +114,11 @@ export async function resolveWorktreeIncludePaths(
     if (!patterns.some((pattern) => !pattern.negated)) {
       return []
     }
+    const ignoreCaseTimeout = deadline - Date.now()
+    if (ignoreCaseTimeout <= 0) {
+      throw new Error(`${WORKTREE_INCLUDE_FILE} resolution timed out`)
+    }
+    const ignoreCase = await getWorktreeIncludeIgnoreCase(repoPath, options, ignoreCaseTimeout)
 
     const candidates = new Map<string, GitignoredEntry>()
     let candidateBytes = 0
@@ -134,7 +140,13 @@ export async function resolveWorktreeIncludePaths(
     const addCandidate = (entry: GitignoredEntry): void => {
       if (
         isSafeIncludeCandidate(entry.relativePath) &&
-        isIncludedByWorktreePatterns(patterns, entry.relativePath, entry.isDirectory, matchBudget)
+        isIncludedByWorktreePatterns(
+          patterns,
+          entry.relativePath,
+          entry.isDirectory,
+          matchBudget,
+          ignoreCase
+        )
       ) {
         if (hasCandidateDirectoryAncestor(candidates, entry.relativePath)) {
           return
@@ -246,14 +258,14 @@ export async function resolveWorktreeIncludePaths(
     // Why: Git 2.25's directory collapsing can stop at an untracked parent, so targeted scans preserve nested matches without expanding unrelated ignored trees.
     const filePathspecs = [
       ...broadPatterns.flatMap((pattern) => [
-        ...(pattern.dirOnly ? [] : [worktreeIncludePatternToGitPathspec(pattern)]),
+        ...(pattern.dirOnly ? [] : [worktreeIncludePatternToGitPathspec(pattern, ignoreCase)]),
         // Why: files beneath a matching directory expose directory matches that
         // Git 2.25 otherwise hides behind a collapsed ignored parent.
-        worktreeIncludePatternToGitDescendantPathspec(pattern)
+        worktreeIncludePatternToGitDescendantPathspec(pattern, ignoreCase)
       ]),
       ...Array.from(anchoredLiteralDirectories.entries())
         .filter(([relativePath]) => !ignoredAnchoredDirectories.has(relativePath))
-        .map(([, pattern]) => worktreeIncludePatternToGitDescendantPathspec(pattern))
+        .map(([, pattern]) => worktreeIncludePatternToGitDescendantPathspec(pattern, ignoreCase))
     ]
     if (filePathspecs.length > 0) {
       // Why: collapsed directories are already copied as units; excluding them
diff --git a/src/main/git/worktree-include-flow.test.ts b/src/main/git/worktree-include-flow.test.ts
index b90d810f1e4..b390ab33557 100644
--- a/src/main/git/worktree-include-flow.test.ts
+++ b/src/main/git/worktree-include-flow.test.ts
@@ -33,6 +33,7 @@ describe('worktree include creation flow', () => {
   })
 
   it('copies only matched ignored paths and leaves ordinary removal clean', async () => {
+    await git(['config', 'core.ignoreCase', 'true'])
     await writeFile(join(primary, '.gitignore'), '.env\ncache/\nparent/\nmixed/local.txt\n')
     await writeFile(
       join(primary, '.worktreeinclude'),
@@ -42,6 +43,8 @@ describe('worktree include creation flow', () => {
     await writeFile(join(primary, '.env'), 'ROOT=1\n')
     await mkdir(join(primary, 'apps', 'web'), { recursive: true })
     await writeFile(join(primary, 'apps', 'web', '.env'), 'NESTED=1\n')
+    await mkdir(join(primary, 'case'))
+    await writeFile(join(primary, 'case', '.ENV'), 'CASE=1\n')
     await mkdir(join(primary, 'cache'))
     await writeFile(join(primary, 'cache', 'artifact'), 'cached\n')
     await mkdir(join(primary, 'parent', 'build'), { recursive: true })
@@ -58,6 +61,7 @@ describe('worktree include creation flow', () => {
       '.env',
       'apps/web/.env',
       'cache',
+      'case/.ENV',
       'mixed/local.txt',
       'parent/build/marker'
     ])
@@ -67,6 +71,7 @@ describe('worktree include creation flow', () => {
     expect(await readFile(join(worktree, '.env'), 'utf8')).toBe('ROOT=1\n')
     expect(await readFile(join(worktree, 'apps', 'web', '.env'), 'utf8')).toBe('NESTED=1\n')
     expect(await readFile(join(worktree, 'cache', 'artifact'), 'utf8')).toBe('cached\n')
+    expect(await readFile(join(worktree, 'case', '.ENV'), 'utf8')).toBe('CASE=1\n')
     expect(await readFile(join(worktree, 'mixed', 'local.txt'), 'utf8')).toBe('local\n')
     expect(await readFile(join(worktree, 'mixed', 'tracked.txt'), 'utf8')).toBe('tracked\n')
     expect(await readFile(join(worktree, 'parent', 'build', 'marker'), 'utf8')).toBe('built\n')
diff --git a/src/main/git/worktree-include-git-enumeration.ts b/src/main/git/worktree-include-git-enumeration.ts
index 38a4682400c..01d60ffbec3 100644
--- a/src/main/git/worktree-include-git-enumeration.ts
+++ b/src/main/git/worktree-include-git-enumeration.ts
@@ -18,6 +18,28 @@ type ListGitignoredEntriesOptions = {
   timeout: number
 }
 
+type GitExecError = Error & { code?: number | string }
+
+export async function getWorktreeIncludeIgnoreCase(
+  repoPath: string,
+  options: GitRuntimeOptions,
+  timeout: number
+): Promise<boolean> {
+  try {
+    const { stdout } = await gitExecFileAsync(['config', '--bool', 'core.ignoreCase'], {
+      ...gitOptionsForWorktree(repoPath, options),
+      timeout
+    })
+    return stdout.trim() === 'true'
+  } catch (error) {
+    const code = (error as GitExecError).code
+    if (code === 1 || code === '1') {
+      return false
+    }
+    throw error
+  }
+}
+
 export async function listGitignoredEntries(
   repoPath: string,
   options: GitRuntimeOptions,
@@ -53,16 +75,20 @@ export async function listGitignoredEntries(
   return entries
 }
 
-export function worktreeIncludePatternToGitPathspec(pattern: WorktreeIncludePattern): string {
+export function worktreeIncludePatternToGitPathspec(
+  pattern: WorktreeIncludePattern,
+  ignoreCase: boolean = false
+): string {
   // Why: our matcher treats `[` literally, while Git pathspec globs treat it as a character class opener.
   const body = pattern.body.replaceAll('[', '[[]')
-  return `:(glob)${pattern.anchored ? '' : '**/'}${body}`
+  return `:(${ignoreCase ? 'icase,' : ''}glob)${pattern.anchored ? '' : '**/'}${body}`
 }
 
 export function worktreeIncludePatternToGitDescendantPathspec(
-  pattern: WorktreeIncludePattern
+  pattern: WorktreeIncludePattern,
+  ignoreCase: boolean = false
 ): string {
-  return `${worktreeIncludePatternToGitPathspec(pattern)}/**`
+  return `${worktreeIncludePatternToGitPathspec(pattern, ignoreCase)}/**`
 }
 
 export function chunkWorktreeIncludePathspecs(
diff --git a/src/main/git/worktree-include-glob.ts b/src/main/git/worktree-include-glob.ts
index a4946f6b478..f8a110bc5f5 100644
--- a/src/main/git/worktree-include-glob.ts
+++ b/src/main/git/worktree-include-glob.ts
@@ -1,5 +1,5 @@
 type WorktreeIncludeGlobToken =
-  | { kind: 'literal'; value: string }
+  | { kind: 'literal'; value: string; caseFoldedValue: string }
   | { kind: 'one' }
   | { kind: 'segment-star' }
   | { kind: 'recursive-star' }
@@ -7,6 +7,7 @@ type WorktreeIncludeGlobToken =
 
 export type CompiledWorktreeIncludeGlob = {
   regExp: RegExp | null
+  ignoreCaseRegExp: RegExp | null | undefined
   tokens: readonly WorktreeIncludeGlobToken[]
   variableWidthSuffixLength: number | null
 }
@@ -36,7 +37,7 @@ export function compileWorktreeIncludeGlob(pattern: string): CompiledWorktreeInc
       tokens.push({ kind: 'one' })
       regex += '[^/]'
     } else {
-      tokens.push({ kind: 'literal', value: char })
+      tokens.push({ kind: 'literal', value: char, caseFoldedValue: char.toLowerCase() })
       regex += char.replace(/[.+^${}()|[\]\\]/, '\\$&')
     }
   }
@@ -46,6 +47,7 @@ export function compileWorktreeIncludeGlob(pattern: string): CompiledWorktreeInc
   return {
     // Why: multiple variable-width groups can make JS regex backtracking exponential.
     regExp: starCount <= 1 ? new RegExp(`^${regex}$`) : null,
+    ignoreCaseRegExp: starCount <= 1 ? undefined : null,
     tokens,
     variableWidthSuffixLength:
       variableWidthIndex === -1 ? null : tokens.length - variableWidthIndex - 1
@@ -68,12 +70,18 @@ export function getWorktreeIncludeGlobStepCount(
 
 export function matchesWorktreeIncludeGlob(
   pattern: CompiledWorktreeIncludeGlob,
-  value: string
+  value: string,
+  ignoreCase: boolean = false
 ): boolean {
   if (pattern.regExp !== null) {
-    return pattern.regExp.test(value)
+    if (!ignoreCase) {
+      return pattern.regExp.test(value)
+    }
+    pattern.ignoreCaseRegExp ??= new RegExp(pattern.regExp.source, 'i')
+    return pattern.ignoreCaseRegExp.test(value)
   }
 
+  const comparableValue = ignoreCase ? value.toLowerCase() : value
   let previous = new Uint8Array(value.length + 1)
   previous[0] = 1
   for (const token of pattern.tokens) {
@@ -81,19 +89,23 @@ export function matchesWorktreeIncludeGlob(
     if (token.kind === 'segment-star' || token.kind === 'recursive-star') {
       current[0] = previous[0]
       for (let index = 1; index <= value.length; index++) {
-        const canConsume = token.kind === 'recursive-star' || value[index - 1] !== '/'
+        const canConsume = token.kind === 'recursive-star' || comparableValue[index - 1] !== '/'
         current[index] = previous[index] || (canConsume && current[index - 1]) ? 1 : 0
       }
     } else if (token.kind === 'optional-slash') {
       current[0] = previous[0]
       for (let index = 1; index <= value.length; index++) {
         current[index] =
-          previous[index] || (value[index - 1] === '/' && previous[index - 1]) ? 1 : 0
+          previous[index] || (comparableValue[index - 1] === '/' && previous[index - 1]) ? 1 : 0
       }
     } else {
       for (let index = 1; index <= value.length; index++) {
         const matches =
-          token.kind === 'one' ? value[index - 1] !== '/' : value[index - 1] === token.value
+          token.kind === 'one'
+            ? comparableValue[index - 1] !== '/'
+            : ignoreCase
+              ? comparableValue[index - 1] === token.caseFoldedValue
+              : comparableValue[index - 1] === token.value
         current[index] = previous[index - 1] && matches ? 1 : 0
       }
     }
diff --git a/src/main/git/worktree-include-pattern.ts b/src/main/git/worktree-include-pattern.ts
index acb62a975f8..18161d05604 100644
--- a/src/main/git/worktree-include-pattern.ts
+++ b/src/main/git/worktree-include-pattern.ts
@@ -13,6 +13,7 @@ export type WorktreeIncludePattern = {
   negated: boolean
   /** Pattern with `!`, leading `/`, and trailing `/` stripped. */
   body: string
+  caseFoldedBody: string
   dirOnly: boolean
   anchored: boolean
   hasGlob: boolean
@@ -41,6 +42,7 @@ export function parseWorktreeIncludePatterns(content: string): WorktreeIncludePa
     patterns.push({
       negated,
       body: trimmed,
+      caseFoldedBody: trimmed.toLowerCase(),
       dirOnly,
       anchored,
       hasGlob,
@@ -63,34 +65,39 @@ function spendMatchBudget(budget: WorktreeIncludeMatchBudget, steps: number): vo
 function globMatches(
   pattern: WorktreeIncludePattern,
   subject: string,
-  budget: WorktreeIncludeMatchBudget
+  budget: WorktreeIncludeMatchBudget,
+  ignoreCase: boolean
 ): boolean {
   if (pattern.glob === null) {
     return false
   }
   spendMatchBudget(budget, getWorktreeIncludeGlobStepCount(pattern.glob, subject))
-  return matchesWorktreeIncludeGlob(pattern.glob, subject)
+  return matchesWorktreeIncludeGlob(pattern.glob, subject, ignoreCase)
 }
 
 function patternMatches(
   pattern: WorktreeIncludePattern,
   relativePath: string,
+  caseFoldedRelativePath: string,
   isDirectory: boolean,
-  budget: WorktreeIncludeMatchBudget
+  budget: WorktreeIncludeMatchBudget,
+  ignoreCase: boolean
 ): boolean {
+  // Why: directory-only rules can reject root files before glob evaluation, so charge the otherwise-free scan.
+  spendMatchBudget(budget, relativePath.length + 1)
   if (!pattern.hasGlob) {
+    const matchPath = ignoreCase ? caseFoldedRelativePath : relativePath
+    const matchBody = ignoreCase ? pattern.caseFoldedBody : pattern.body
     if (pattern.anchored) {
-      spendMatchBudget(budget, relativePath.length + 1)
       return (
-        (relativePath === pattern.body && (!pattern.dirOnly || isDirectory)) ||
-        relativePath.startsWith(`${pattern.body}/`)
+        (matchPath === matchBody && (!pattern.dirOnly || isDirectory)) ||
+        matchPath.startsWith(`${matchBody}/`)
       )
     }
-    const segments = relativePath.split('/')
+    const segments = matchPath.split('/')
     const lastMatchableIndex =
       pattern.dirOnly && !isDirectory ? segments.length - 2 : segments.length - 1
-    spendMatchBudget(budget, relativePath.length + 1)
-    return segments.slice(0, lastMatchableIndex + 1).includes(pattern.body)
+    return segments.slice(0, lastMatchableIndex + 1).includes(matchBody)
   }
 
   const segments = relativePath.split('/')
@@ -101,7 +108,7 @@ function patternMatches(
   }
   if (!pattern.anchored) {
     for (let index = 0; index <= lastMatchableIndex; index++) {
-      if (globMatches(pattern, segments[index], budget)) {
+      if (globMatches(pattern, segments[index], budget, ignoreCase)) {
         return true
       }
     }
@@ -111,7 +118,7 @@ function patternMatches(
   let prefix = ''
   for (let index = 0; index <= lastMatchableIndex; index++) {
     prefix = prefix ? `${prefix}/${segments[index]}` : segments[index]
-    if (globMatches(pattern, prefix, budget)) {
+    if (globMatches(pattern, prefix, budget, ignoreCase)) {
       return true
     }
   }
@@ -122,12 +129,16 @@ export function isIncludedByWorktreePatterns(
   patterns: readonly WorktreeIncludePattern[],
   relativePath: string,
   isDirectory: boolean,
-  budget: WorktreeIncludeMatchBudget
+  budget: WorktreeIncludeMatchBudget,
+  ignoreCase: boolean = false
 ): boolean {
   // Why: gitignore patterns are order-sensitive, so negations must use last-match-wins.
   let included = false
+  const caseFoldedRelativePath = ignoreCase ? relativePath.toLowerCase() : relativePath
   for (const pattern of patterns) {
-    if (patternMatches(pattern, relativePath, isDirectory, budget)) {
+    if (
+      patternMatches(pattern, relativePath, caseFoldedRelativePath, isDirectory, budget, ignoreCase)
+    ) {
       included = !pattern.negated
     }
   }
diff --git a/src/main/git/worktree-include-stat-concurrency.test.ts b/src/main/git/worktree-include-stat-concurrency.test.ts
index 4426e2be904..52ab005e643 100644
--- a/src/main/git/worktree-include-stat-concurrency.test.ts
+++ b/src/main/git/worktree-include-stat-concurrency.test.ts
@@ -49,7 +49,7 @@ describe('worktree include stat concurrency', () => {
 
     expect(peak).toBe(8)
     expect(lstatMock).toHaveBeenCalledTimes(25)
-    expect(gitExecFileAsync).toHaveBeenCalledTimes(1)
+    expect(gitExecFileAsync).toHaveBeenCalledTimes(2)
   })
 
   it('stops starting filesystem probes when the resolution deadline expires', async () => {
@@ -63,12 +63,13 @@ describe('worktree include stat concurrency', () => {
       }
       return new Promise(() => {})
     })
+    vi.mocked(gitExecFileAsync).mockRejectedValue(Object.assign(new Error('unset'), { code: 1 }))
 
     const resolution = resolveWorktreeIncludePaths('/repo')
     await vi.advanceTimersByTimeAsync(15_000)
 
     await expect(resolution).resolves.toEqual([])
     expect(lstatMock).toHaveBeenCalledTimes(9)
-    expect(gitExecFileAsync).not.toHaveBeenCalled()
+    expect(gitExecFileAsync).toHaveBeenCalledTimes(1)
   })
 })
diff --git a/src/shared/git-binary-compatibility.test.ts b/src/shared/git-binary-compatibility.test.ts
index 2b471b006c5..7b35444d3bf 100644
--- a/src/shared/git-binary-compatibility.test.ts
+++ b/src/shared/git-binary-compatibility.test.ts
@@ -175,7 +175,7 @@ describeBinaryCompatibility('real Git binary compatibility', () => {
   })
 
   it('lists collapsed directories and targeted nested files for worktree includes', async () => {
-    await writeFile(join(repoPath, '.gitignore'), '.env\ncache/\nbuild/\nparent/\n')
+    await writeFile(join(repoPath, '.gitignore'), '.env\ncache/\nbuild/\nparent/\ncase/\n')
     await writeFile(join(repoPath, '.env'), 'ROOT=1\n')
     await mkdir(join(repoPath, 'apps', 'web'), { recursive: true })
     await writeFile(join(repoPath, 'apps', 'web', '.env'), 'NESTED=1\n')
@@ -185,6 +185,8 @@ describeBinaryCompatibility('real Git binary compatibility', () => {
     await writeFile(join(repoPath, 'build', 'root-artifact'), 'ignored\n')
     await mkdir(join(repoPath, 'parent', 'build'), { recursive: true })
     await writeFile(join(repoPath, 'parent', 'build', 'nested-artifact'), 'ignored\n')
+    await mkdir(join(repoPath, 'case'))
+    await writeFile(join(repoPath, 'case', '.ENV'), 'CASE=1\n')
 
     const collapsed = await runGit([
       '-c',
@@ -214,6 +216,19 @@ describeBinaryCompatibility('real Git binary compatibility', () => {
     ])
     expect(targeted.stdout.split('\0').filter(Boolean)).toEqual(['.env', 'apps/web/.env'])
 
+    const caseInsensitiveTargeted = await runGit([
+      '-c',
+      'core.quotePath=false',
+      'ls-files',
+      '--others',
+      '--ignored',
+      '--exclude-standard',
+      '-z',
+      '--',
+      ':(icase,glob)**/.env'
+    ])
+    expect(caseInsensitiveTargeted.stdout.split('\0').filter(Boolean)).toContain('case/.ENV')
+
     const targetedDirectory = await runGit([
       '-c',
       'core.quotePath=false',