diff --git a/apps/web/src/app/(onboarding)/setup/StepRepoSelection.client.test.tsx b/apps/web/src/app/(onboarding)/setup/StepRepoSelection.client.test.tsx
index bb98803b8..4c7737a9c 100644
--- a/apps/web/src/app/(onboarding)/setup/StepRepoSelection.client.test.tsx
+++ b/apps/web/src/app/(onboarding)/setup/StepRepoSelection.client.test.tsx
@@ -273,6 +273,7 @@ vi.mock('@/components/system', () => ({
   Input: (props: InputHTMLAttributes<HTMLInputElement>) => <input {...props} />,
   ArrowRight: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   Loader2: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
+  PackagePlus: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   Plus: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   RefreshCcw: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   RotateCw: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
diff --git a/apps/web/src/app/(onboarding)/setup/StepRepoSelection.tsx b/apps/web/src/app/(onboarding)/setup/StepRepoSelection.tsx
index dc3f9fc72..ce74e3b60 100644
--- a/apps/web/src/app/(onboarding)/setup/StepRepoSelection.tsx
+++ b/apps/web/src/app/(onboarding)/setup/StepRepoSelection.tsx
@@ -532,6 +532,7 @@ export function StepRepoSelection({
                 selectedRepositoryIds={selectedRepositoryIds}
                 onToggleRepository={toggleRepository}
                 onCreateRepository={() => setCreateRepoDialogOpen(true)}
+                showSearch={false}
                 inputPrefix="setup-repository"
                 heightClassName="max-h-[calc(var(--effective-viewport-height)-40rem)] md:h-[18.75rem]"
               />
diff --git a/apps/web/src/components/settings/environments/CreateEnvironmentPage.client.test.tsx b/apps/web/src/components/settings/environments/CreateEnvironmentPage.client.test.tsx
index a21e975bb..088e0d947 100644
--- a/apps/web/src/components/settings/environments/CreateEnvironmentPage.client.test.tsx
+++ b/apps/web/src/components/settings/environments/CreateEnvironmentPage.client.test.tsx
@@ -263,8 +263,11 @@ vi.mock('@/components/system', () => ({
   ),
   HandMetal: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   Info: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
+  Input: (props: InputHTMLAttributes<HTMLInputElement>) => <input {...props} />,
   Loader2: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
+  PackagePlus: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   Plus: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
+  Search: (props: SVGProps<SVGSVGElement>) => <svg {...props} />,
   ScrollArea: ({
     children,
     ...props
diff --git a/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.client.test.tsx b/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.client.test.tsx
new file mode 100644
index 000000000..6bfb4fd98
--- /dev/null
+++ b/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.client.test.tsx
@@ -0,0 +1,141 @@
+import { useState } from 'react';
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
+
+import { EnvironmentRepositorySelector } from './EnvironmentRepositorySelector';
+
+const repositories = [
+  { id: 'repo-web', fullName: 'Acme/web' },
+  { id: 'repo-api', fullName: 'acme/api' },
+  { id: 'repo-roomote', fullName: 'RoomoteInc/Roomote' },
+];
+
+function SelectorHarness({
+  initialSelection = [],
+  onCreateRepository,
+}: {
+  initialSelection?: string[];
+  onCreateRepository?: () => void;
+}) {
+  const [selectedRepositoryIds, setSelectedRepositoryIds] =
+    useState(initialSelection);
+
+  return (
+    <EnvironmentRepositorySelector
+      repositories={repositories}
+      selectedRepositoryIds={selectedRepositoryIds}
+      onToggleRepository={(repositoryId) =>
+        setSelectedRepositoryIds((currentSelection) =>
+          currentSelection.includes(repositoryId)
+            ? currentSelection.filter((id) => id !== repositoryId)
+            : [...currentSelection, repositoryId],
+        )
+      }
+      onCreateRepository={onCreateRepository}
+      inputPrefix="test-repository"
+    />
+  );
+}
+
+describe('EnvironmentRepositorySelector', () => {
+  it('filters repository full names case-insensitively and restores sorted results', async () => {
+    render(<SelectorHarness />);
+
+    expect(
+      screen.getAllByRole('checkbox').map((checkbox) => checkbox.id),
+    ).toEqual([
+      'test-repository-repo-api',
+      'test-repository-repo-web',
+      'test-repository-repo-roomote',
+    ]);
+
+    const search = screen.getByRole('searchbox', {
+      name: 'Search repositories',
+    });
+    fireEvent.change(search, { target: { value: 'ROOMOTE' } });
+
+    await waitFor(() => {
+      expect(screen.getByText('RoomoteInc/Roomote')).toBeInTheDocument();
+      expect(screen.queryByText('acme/api')).not.toBeInTheDocument();
+    });
+
+    fireEvent.change(search, { target: { value: '' } });
+
+    await waitFor(() => {
+      expect(screen.getAllByRole('checkbox')).toHaveLength(3);
+    });
+  });
+
+  it('preserves selected repositories while they are filtered out', async () => {
+    render(<SelectorHarness initialSelection={['repo-web']} />);
+
+    const search = screen.getByRole('searchbox', {
+      name: 'Search repositories',
+    });
+    fireEvent.change(search, { target: { value: 'api' } });
+
+    await waitFor(() => {
+      expect(screen.queryByText('Acme/web')).not.toBeInTheDocument();
+    });
+
+    fireEvent.change(search, { target: { value: '' } });
+
+    await waitFor(() => {
+      expect(screen.getByLabelText('Acme/web')).toBeChecked();
+    });
+  });
+
+  it('keeps repository creation available when no repositories match', async () => {
+    const onCreateRepository = vi.fn();
+    render(<SelectorHarness onCreateRepository={onCreateRepository} />);
+
+    fireEvent.change(
+      screen.getByRole('searchbox', { name: 'Search repositories' }),
+      { target: { value: 'missing' } },
+    );
+
+    await waitFor(() => {
+      expect(screen.getByText('No repositories found.')).toBeInTheDocument();
+    });
+
+    fireEvent.click(
+      screen.getByRole('button', { name: 'Create a new repository' }),
+    );
+    expect(onCreateRepository).toHaveBeenCalledOnce();
+  });
+
+  it('omits search for an empty list while retaining repository creation', () => {
+    const onCreateRepository = vi.fn();
+
+    render(
+      <EnvironmentRepositorySelector
+        repositories={[]}
+        selectedRepositoryIds={[]}
+        onToggleRepository={vi.fn()}
+        onCreateRepository={onCreateRepository}
+      />,
+    );
+
+    expect(
+      screen.queryByRole('searchbox', { name: 'Search repositories' }),
+    ).not.toBeInTheDocument();
+    expect(
+      screen.getByRole('button', { name: 'Create a new repository' }),
+    ).toBeInTheDocument();
+  });
+
+  it('allows callers with an existing filter to suppress search', () => {
+    render(
+      <EnvironmentRepositorySelector
+        repositories={repositories}
+        selectedRepositoryIds={[]}
+        onToggleRepository={vi.fn()}
+        showSearch={false}
+      />,
+    );
+
+    expect(
+      screen.queryByRole('searchbox', { name: 'Search repositories' }),
+    ).not.toBeInTheDocument();
+    expect(screen.getAllByRole('checkbox')).toHaveLength(3);
+  });
+});
diff --git a/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.tsx b/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.tsx
index 6199d3528..0b7d2926e 100644
--- a/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.tsx
+++ b/apps/web/src/components/settings/environments/EnvironmentRepositorySelector.tsx
@@ -1,9 +1,14 @@
 'use client';
 
-import { useMemo } from 'react';
+import { useDeferredValue, useMemo, useState } from 'react';
 
-import { Checkbox, ScrollArea } from '@/components/system';
-import { PackagePlus } from 'lucide-react';
+import {
+  Checkbox,
+  Input,
+  PackagePlus,
+  ScrollArea,
+  Search,
+} from '@/components/system';
 
 type RepositorySummary = {
   id: string;
@@ -15,6 +20,7 @@ export function EnvironmentRepositorySelector({
   selectedRepositoryIds,
   onToggleRepository,
   onCreateRepository,
+  showSearch = true,
   inputPrefix = 'environment-repository',
   heightClassName = 'max-h-[11.5rem] md:h-[18.75rem]',
 }: {
@@ -22,9 +28,12 @@ export function EnvironmentRepositorySelector({
   selectedRepositoryIds: string[];
   onToggleRepository: (repositoryId: string) => void;
   onCreateRepository?: () => void;
+  showSearch?: boolean;
   inputPrefix?: string;
   heightClassName?: string;
 }) {
+  const [search, setSearch] = useState('');
+  const normalizedSearch = useDeferredValue(search.trim().toLowerCase());
   const sortedRepositories = useMemo(
     () =>
       [...repositories].sort((left, right) =>
@@ -32,10 +41,34 @@ export function EnvironmentRepositorySelector({
       ),
     [repositories],
   );
+  const filteredRepositories = useMemo(() => {
+    if (!normalizedSearch) {
+      return sortedRepositories;
+    }
+
+    return sortedRepositories.filter((repository) =>
+      repository.fullName.toLowerCase().includes(normalizedSearch),
+    );
+  }, [normalizedSearch, sortedRepositories]);
 
   return (
     <ScrollArea className={`overflow-auto ${heightClassName}`}>
       <div className="space-y-1">
+        {showSearch && repositories.length > 0 ? (
+          <div className="sticky top-0 z-10 bg-card pb-2">
+            <div className="relative">
+              <Search className="pointer-events-none absolute top-1/2 left-3 size-4 -translate-y-1/2 text-muted-foreground" />
+              <Input
+                type="search"
+                aria-label="Search repositories"
+                placeholder="Search repositories…"
+                value={search}
+                onChange={(event) => setSearch(event.currentTarget.value)}
+                className="pl-9"
+              />
+            </div>
+          </div>
+        ) : null}
         {onCreateRepository ? (
           <p className="border-b border-dotted pb-1">
             <button
@@ -48,21 +81,27 @@ export function EnvironmentRepositorySelector({
             </button>
           </p>
         ) : null}
-        {sortedRepositories.map((repository) => (
-          <label
-            key={repository.id}
-            className="flex cursor-pointer items-start gap-3 rounded-md py-1 text-foreground transition-colors hover:bg-muted/30"
-            htmlFor={`${inputPrefix}-${repository.id}`}
-          >
-            <Checkbox
-              id={`${inputPrefix}-${repository.id}`}
-              checked={selectedRepositoryIds.includes(repository.id)}
-              onCheckedChange={() => onToggleRepository(repository.id)}
-              className="mt-0.5"
-            />
-            <div className="min-w-0 flex-1">{repository.fullName}</div>
-          </label>
-        ))}
+        {filteredRepositories.length === 0 && normalizedSearch ? (
+          <p className="py-6 text-center text-sm text-muted-foreground">
+            No repositories found.
+          </p>
+        ) : (
+          filteredRepositories.map((repository) => (
+            <label
+              key={repository.id}
+              className="flex cursor-pointer items-start gap-3 rounded-md py-1 text-foreground transition-colors hover:bg-muted/30"
+              htmlFor={`${inputPrefix}-${repository.id}`}
+            >
+              <Checkbox
+                id={`${inputPrefix}-${repository.id}`}
+                checked={selectedRepositoryIds.includes(repository.id)}
+                onCheckedChange={() => onToggleRepository(repository.id)}
+                className="mt-0.5"
+              />
+              <div className="min-w-0 flex-1">{repository.fullName}</div>
+            </label>
+          ))
+        )}
       </div>
     </ScrollArea>
   );
diff --git a/apps/web/src/components/system/primitives/icons.ts b/apps/web/src/components/system/primitives/icons.ts
index c4d10f058..2c1abc164 100644
--- a/apps/web/src/components/system/primitives/icons.ts
+++ b/apps/web/src/components/system/primitives/icons.ts
@@ -141,6 +141,7 @@ export {
   Music2Icon,
   PanelLeftClose,
   PanelLeftOpen,
+  PackagePlus,
   PaperclipIcon,
   Pencil,
   Pin,