diff --git a/.changeset/4919-retire-mobile-overrides.md b/.changeset/4919-retire-mobile-overrides.md
new file mode 100644
index 000000000..2e0d9a445
--- /dev/null
+++ b/.changeset/4919-retire-mobile-overrides.md
@@ -0,0 +1,46 @@
+---
+'@object-ui/types': minor
+'@object-ui/mobile': minor
+---
+
+Retire the `MobileOverrides` type and its `mobileOverrides` mount point (objectui#4919,
+maintainer ruling 2026-08-19, ADR-0049 enforce-or-remove).
+
+`MobileOverrides` published a six-key mobile override surface — `layout`, `columns`,
+`useBottomSheet`, `fullScreen`, `touchTarget` and a three-value `navigation` vocabulary
+(`'bottom-tabs' | 'hamburger' | 'drawer'`) — from `@object-ui/types` and, re-exported,
+from `@object-ui/mobile`. Nothing read any of it. Measured on current `main`: the type had
+exactly four mentions repo-wide — its own declaration, the single
+`MobileComponentConfig.mobileOverrides` mount point, and the two barrel re-exports — and
+the lower-case property name (the spelling a renderer would actually read) appeared only
+in that declaration. No renderer, hook or adapter resolved it, and a sweep of the example
+apps and the `objectstack` sibling checkout found zero authors. The three `navigation`
+values were three spellings of the same no-op.
+
+The declared surface is removed rather than narrowed. The #3985 lineage's rule is "narrow
+to the implemented values"; here the implemented set is empty, so that rule terminates in
+deletion — a config that type-checks, builds and silently does nothing is the
+declare-without-enforce shape the platform doctrine forbids.
+
+Removal rather than a `?: never` tombstone follows this package's own discriminator. A
+tombstone exists to steer authors to a named live replacement — `crud.ts` `confirm` →
+`confirmText` (objectui#4314), `data-display.ts` `hoverable` / `striped` → `data-table`
+(objectui#5474) — or to keep a key loud that the docs had actively taught as working.
+Neither applies: there is no replacement key to steer to, no documentation ever described
+the surface, and there is no successor spelling. That is the same zero-pull, no-successor
+shape as the retired `AccordionItem.icon` (objectui#4652) and `ToggleGroupItem.icon`
+(objectui#4632), both of which were removed outright rather than tombstoned.
+
+**Breaking for TypeScript authors of `MobileOverrides` / `mobileOverrides` only** (marked
+`minor` per this repo's version-alignment rule, which reserves `major` for following
+`@objectstack` across a major — see AGENTS.md's 版本号策略, and the identical
+classification used for `AccordionItem.icon`). Runtime behaviour is unchanged: an authored
+`mobileOverrides` did nothing before and does nothing now. What changes is that the
+contract no longer claims otherwise, so the mistake surfaces at authoring time — importing
+the type is now a "has no exported member" error, and authoring the key on a
+`MobileComponentConfig` object literal is an excess-property error, instead of a silent
+no-op that type-checks and builds.
+
+If real mobile-override renderer work is ever wanted it re-enters deliberately, as designed
+product surface on its own card, with the renderer landing in the same change as the
+declaration — not by resurrecting this declaration.
diff --git a/packages/mobile/src/index.ts b/packages/mobile/src/index.ts
index 5837a5d7d..7fc4727b7 100644
--- a/packages/mobile/src/index.ts
+++ b/packages/mobile/src/index.ts
@@ -57,7 +57,6 @@ export type {
   BreakpointName,
   ResponsiveValue,
   MobileResponsiveConfig,
-  MobileOverrides,
   PWAConfig,
   PWAIcon,
   FetchCacheStrategy,
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index c2e3ba13a..4b3b8fa30 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -582,7 +582,6 @@ export type {
   BreakpointName,
   ResponsiveValue,
   MobileResponsiveConfig,
-  MobileOverrides,
   PWAConfig,
   PWAIcon,
   FetchCacheStrategy,
diff --git a/packages/types/src/mobile.ts b/packages/types/src/mobile.ts
index ff21f0dec..a4f228ef6 100644
--- a/packages/types/src/mobile.ts
+++ b/packages/types/src/mobile.ts
@@ -69,21 +69,25 @@ export interface MobileResponsiveConfig {
   showOnly?: BreakpointName[];
 }
 
-/** Mobile-specific component overrides */
-export interface MobileOverrides {
-  /** Simplified layout for mobile */
-  layout?: 'stack' | 'tabs' | 'accordion' | 'carousel';
-  /** Reduced columns for forms */
-  columns?: number;
-  /** Whether to use bottom sheet instead of modal */
-  useBottomSheet?: boolean;
-  /** Whether to use full-screen mode */
-  fullScreen?: boolean;
-  /** Touch-friendly sizing */
-  touchTarget?: 'default' | 'large' | 'xlarge';
-  /** Simplified navigation */
-  navigation?: 'bottom-tabs' | 'hamburger' | 'drawer';
-}
+// RETIRED (objectui#4919, maintainer ruling 2026-08-19, ADR-0049
+// enforce-or-remove): the mobile component-override surface and its mount
+// point on `MobileComponentConfig` are gone, not narrowed. Every member was
+// declaration-only — nothing in this repo, the example apps, or the
+// `objectstack` sibling checkout ever read the property, so all six keys
+// behaved identically (they did nothing), and the navigation vocabulary's
+// three values were three spellings of the same no-op. Removal rather than a
+// `?: never` tombstone follows this package's own discriminator: a tombstone
+// exists to steer authors to a named live replacement (`crud.ts` `confirm` →
+// `confirmText`; `data-display.ts` `hoverable`/`striped` → `data-table`),
+// and there is no replacement here — the same zero-pull/no-successor shape as
+// the retired `AccordionItem.icon` / `ToggleGroupItem.icon`, which were
+// likewise removed outright rather than tombstoned.
+//
+// Reopen condition, recorded on objectui#4919: real mobile-override renderer
+// work re-enters as designed product surface on its own card, with the
+// renderer landing in the same change as the declaration. Re-adding the
+// declaration alone is the declare-without-enforce shape this removal exists
+// to close.
 
 // ============================================================================
 // PWA Support
@@ -279,8 +283,6 @@ export interface GestureContext {
 export interface MobileComponentConfig {
   /** Responsive configuration */
   responsive?: MobileResponsiveConfig;
-  /** Mobile-specific overrides */
-  mobileOverrides?: MobileOverrides;
   /** Touch gesture handlers */
   gestures?: GestureConfig[];
   /** Pull-to-refresh configuration */