diff --git a/src/app/c/[slug]/error.test.tsx b/src/app/c/[...slug]/error.test.tsx
similarity index 100%
rename from src/app/c/[slug]/error.test.tsx
rename to src/app/c/[...slug]/error.test.tsx
diff --git a/src/app/c/[slug]/error.tsx b/src/app/c/[...slug]/error.tsx
similarity index 100%
rename from src/app/c/[slug]/error.tsx
rename to src/app/c/[...slug]/error.tsx
diff --git a/src/app/c/[slug]/layout.tsx b/src/app/c/[...slug]/layout.tsx
similarity index 100%
rename from src/app/c/[slug]/layout.tsx
rename to src/app/c/[...slug]/layout.tsx
diff --git a/src/app/c/[slug]/page.test.tsx b/src/app/c/[...slug]/page.test.tsx
similarity index 81%
rename from src/app/c/[slug]/page.test.tsx
rename to src/app/c/[...slug]/page.test.tsx
index b51a349..fe64099 100644
--- a/src/app/c/[slug]/page.test.tsx
+++ b/src/app/c/[...slug]/page.test.tsx
@@ -78,7 +78,7 @@ beforeEach(() => {
   vi.mocked(getPublicSettings).mockResolvedValue(mockPublicSettings)
 })
 
-const params = Promise.resolve({ slug: 'general' })
+const params = Promise.resolve({ slug: ['general'] })
 
 describe('CategoryPage', () => {
   it('renders category name as heading', async () => {
@@ -124,4 +124,23 @@ describe('CategoryPage', () => {
     })
     expect(breadcrumbScript).toBeTruthy()
   })
+
+  it('renders subcategory with parent breadcrumb', async () => {
+    const subcategoryData = {
+      ...mockCategories[2]!.children[1]!, // bug-reports under feedback
+      topicCount: 3,
+    }
+    mockGetCategoryBySlug.mockResolvedValue(subcategoryData)
+    mockGetTopics.mockResolvedValue({ topics: [], cursor: null })
+
+    const subcategoryParams = Promise.resolve({ slug: ['feedback', 'bug-reports'] })
+    const page = await CategoryPage({ params: subcategoryParams })
+    render(page)
+
+    expect(screen.getByRole('heading', { level: 1, name: 'Bug Reports' })).toBeInTheDocument()
+
+    // Parent category should appear in breadcrumbs
+    const breadcrumbNav = screen.getByRole('navigation', { name: /breadcrumb/i })
+    expect(breadcrumbNav).toHaveTextContent('Feedback & Ideas')
+  })
 })
diff --git a/src/app/c/[slug]/page.tsx b/src/app/c/[...slug]/page.tsx
similarity index 69%
rename from src/app/c/[slug]/page.tsx
rename to src/app/c/[...slug]/page.tsx
index 11a7060..d3500dd 100644
--- a/src/app/c/[slug]/page.tsx
+++ b/src/app/c/[...slug]/page.tsx
@@ -1,6 +1,6 @@
 /**
  * Category page - Shows topics for a specific category.
- * URL: /c/{slug}
+ * URL: /c/{slug} or /c/{parentSlug}/{slug} for subcategories.
  * Server-side rendered with SEO metadata and JSON-LD.
  * Maturity-aware: Adult categories are noindex'd, Mature get rating meta.
  * @see specs/prd-web.md Section 3.1
@@ -24,17 +24,34 @@ import { CategoryNav } from '@/components/category-nav'
 import { Breadcrumbs } from '@/components/breadcrumbs'
 import { Pagination } from '@/components/pagination'
 import { NewTopicButton } from '@/components/new-topic-button'
+import type { CategoryTreeNode } from '@/lib/api/types'
 
 interface CategoryPageProps {
-  params: Promise<{ slug: string }>
+  params: Promise<{ slug: string[] }>
   searchParams?: Promise<{ page?: string }>
 }
 
+/** Find a category in the tree by slug. */
+function findCategoryInTree(
+  categories: CategoryTreeNode[],
+  slug: string
+): CategoryTreeNode | undefined {
+  for (const cat of categories) {
+    if (cat.slug === slug) return cat
+    const found = findCategoryInTree(cat.children, slug)
+    if (found) return found
+  }
+  return undefined
+}
+
 export async function generateMetadata({ params }: CategoryPageProps): Promise<Metadata> {
-  const { slug } = await params
+  const { slug: slugSegments } = await params
+  const categorySlug = slugSegments.at(-1)!
+  const canonicalPath = `/c/${slugSegments.join('/')}`
+
   try {
     const [category, publicSettings] = await Promise.all([
-      getCategoryBySlug(slug),
+      getCategoryBySlug(categorySlug),
       getPublicSettings().catch(() => null),
     ])
 
@@ -47,7 +64,7 @@ export async function generateMetadata({ params }: CategoryPageProps): Promise<M
       title: category.name,
       description: category.description ?? `Topics in ${category.name}`,
       alternates: {
-        canonical: `/c/${slug}`,
+        canonical: canonicalPath,
       },
       ...(includeOg
         ? {
@@ -68,13 +85,15 @@ export async function generateMetadata({ params }: CategoryPageProps): Promise<M
 const TOPICS_PER_PAGE = 20
 
 export default async function CategoryPage({ params, searchParams }: CategoryPageProps) {
-  const { slug } = await params
+  const { slug: slugSegments } = await params
+  const categorySlug = slugSegments.at(-1)!
+  const canonicalPath = `/c/${slugSegments.join('/')}`
   const resolvedSearchParams = searchParams ? await searchParams : {}
   const page = Math.max(1, parseInt(resolvedSearchParams.page ?? '1', 10) || 1)
 
   let category
   try {
-    category = await getCategoryBySlug(slug)
+    category = await getCategoryBySlug(categorySlug)
   } catch (error) {
     if (error instanceof ApiError && error.status === 404) {
       notFound()
@@ -85,7 +104,7 @@ export default async function CategoryPage({ params, searchParams }: CategoryPag
   const [categoriesResult, topicsResult, publicSettings] = await Promise.all([
     getCategories(),
     getTopics({
-      category: slug,
+      category: categorySlug,
       limit: TOPICS_PER_PAGE,
     }),
     getPublicSettings().catch(() => null),
@@ -93,15 +112,24 @@ export default async function CategoryPage({ params, searchParams }: CategoryPag
 
   const totalPages = Math.max(1, Math.ceil(category.topicCount / TOPICS_PER_PAGE))
 
-  const breadcrumbItems = [
-    { label: 'Home', href: '/' },
-    { label: category.name, href: `/c/${slug}` },
-  ]
+  // Build breadcrumbs: Home > [Parent] > Category
+  const breadcrumbItems = [{ label: 'Home', href: '/' }]
+
+  if (slugSegments.length > 1) {
+    const parentSlug = slugSegments[0]!
+    const parentCategory = findCategoryInTree(categoriesResult.categories, parentSlug)
+    breadcrumbItems.push({
+      label: parentCategory?.name ?? parentSlug,
+      href: `/c/${parentSlug}`,
+    })
+  }
+
+  breadcrumbItems.push({ label: category.name, href: canonicalPath })
 
   return (
     <ForumLayout
       publicSettings={publicSettings}
-      sidebar={<CategoryNav categories={categoriesResult.categories} currentSlug={slug} />}
+      sidebar={<CategoryNav categories={categoriesResult.categories} currentSlug={categorySlug} />}
     >
       {/* Breadcrumbs (includes JSON-LD BreadcrumbList) */}
       <Breadcrumbs items={breadcrumbItems} />
@@ -119,7 +147,11 @@ export default async function CategoryPage({ params, searchParams }: CategoryPag
 
       {/* New topic button */}
       <div className="mb-4 flex justify-end">
-        <NewTopicButton variant="category" categorySlug={slug} categoryName={category.name} />
+        <NewTopicButton
+          variant="category"
+          categorySlug={categorySlug}
+          categoryName={category.name}
+        />
       </div>
 
       {/* Topic list */}
@@ -128,7 +160,7 @@ export default async function CategoryPage({ params, searchParams }: CategoryPag
       {/* Pagination */}
       {totalPages > 1 && (
         <div className="mt-6">
-          <Pagination currentPage={page} totalPages={totalPages} baseUrl={`/c/${slug}`} />
+          <Pagination currentPage={page} totalPages={totalPages} baseUrl={canonicalPath} />
         </div>
       )}
     </ForumLayout>
diff --git a/src/app/sitemap.test.ts b/src/app/sitemap.test.ts
index 5cbe757..8a5374b 100644
--- a/src/app/sitemap.test.ts
+++ b/src/app/sitemap.test.ts
@@ -118,7 +118,7 @@ describe('sitemap', () => {
     const result = await sitemap()
     const urls = result.map((entry) => entry.url)
     expect(urls).toContain('https://barazo.forum/c/general')
-    expect(urls).toContain('https://barazo.forum/c/introductions')
+    expect(urls).toContain('https://barazo.forum/c/general/introductions')
   })
 
   it('includes topic pages with author handle and rkey', async () => {
@@ -163,7 +163,7 @@ describe('sitemap', () => {
     const urls = result.map((entry) => entry.url)
     // Both parent and child categories should be included
     expect(urls).toContain('https://barazo.forum/c/general')
-    expect(urls).toContain('https://barazo.forum/c/introductions')
+    expect(urls).toContain('https://barazo.forum/c/general/introductions')
   })
 
   it('handles API errors gracefully', async () => {
diff --git a/src/app/sitemap.ts b/src/app/sitemap.ts
index ca44962..e03686a 100644
--- a/src/app/sitemap.ts
+++ b/src/app/sitemap.ts
@@ -12,12 +12,17 @@ import type { CategoryTreeNode } from '@/lib/api/types'
 
 const SITE_URL = process.env.NEXT_PUBLIC_SITE_URL ?? 'https://barazo.forum'
 
-function flattenCategories(nodes: CategoryTreeNode[]): CategoryTreeNode[] {
-  const result: CategoryTreeNode[] = []
+interface FlatCategory extends CategoryTreeNode {
+  path: string
+}
+
+function flattenCategories(nodes: CategoryTreeNode[], parentPath = ''): FlatCategory[] {
+  const result: FlatCategory[] = []
   for (const node of nodes) {
-    result.push(node)
+    const path = parentPath ? `${parentPath}/${node.slug}` : node.slug
+    result.push({ ...node, path })
     if (node.children.length > 0) {
-      result.push(...flattenCategories(node.children))
+      result.push(...flattenCategories(node.children, path))
     }
   }
   return result
@@ -45,7 +50,7 @@ export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
     for (const category of allCategories) {
       if (category.maturityRating === 'adult') continue
       entries.push({
-        url: `${SITE_URL}/c/${category.slug}`,
+        url: `${SITE_URL}/c/${category.path}`,
         lastModified: new Date(category.updatedAt),
         changeFrequency: 'daily',
         priority: 0.8,