diff --git a/.changeset/brave-pandas-smile.md b/.changeset/brave-pandas-smile.md
new file mode 100644
index 00000000000..ee3f77b56c6
--- /dev/null
+++ b/.changeset/brave-pandas-smile.md
@@ -0,0 +1,5 @@
+---
+'@qwik.dev/router': patch
+---
+
+fix: preserve matched params in ancestor layout route loaders
diff --git a/packages/qwik-router/src/middleware/request-handler/handlers/loader-request-event.unit.ts b/packages/qwik-router/src/middleware/request-handler/handlers/loader-request-event.unit.ts
index d3c0bca1122..7b74bca3baa 100644
--- a/packages/qwik-router/src/middleware/request-handler/handlers/loader-request-event.unit.ts
+++ b/packages/qwik-router/src/middleware/request-handler/handlers/loader-request-event.unit.ts
@@ -96,6 +96,8 @@ describe('createLoaderRequestEventFactory', () => {
       const routeLoaderCtx = getRouteLoaderCtx(requestEv);
       routeLoaderCtx.loaderPaths['products-loader'] = '/products/';
       routeLoaderCtx.loaderPaths['details-loader'] = '/products/123/';
+      routeLoaderCtx.loaderParams['products-loader'] = {};
+      routeLoaderCtx.loaderParams['details-loader'] = { id: '123' };
       const getLoaderRequestEvent = createLoaderRequestEventFactory(requestEv);
       const productsLoader = createLoader('products-loader', ['page']);
       const detailsLoader = createLoader('details-loader', ['page']);
@@ -111,6 +113,7 @@ describe('createLoaderRequestEventFactory', () => {
       expect(productsEv.request.url).toBe('http://localhost/products/?page=2');
       expect(productsEv.originalUrl.href).toBe('http://localhost/products/?page=2');
       expect(productsEv.params).toEqual({});
+      expect(detailsEv.params).toEqual({ id: '123' });
     } finally {
       globalThis.__STRICT_LOADERS__ = previousStrictLoaders;
     }
diff --git a/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers-core.ts b/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers-core.ts
index e9ec3aa08d7..2331e36938b 100644
--- a/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers-core.ts
+++ b/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers-core.ts
@@ -363,6 +363,9 @@ function createResolveRequestHandlers() {
     if (route.$loaderPaths$) {
       Object.assign(routeLoaderCtx.loaderPaths, route.$loaderPaths$);
     }
+    if (route.$loaderParams$) {
+      Object.assign(routeLoaderCtx.loaderParams, route.$loaderParams$);
+    }
 
     // Store loader internals so SSG can check __cacheControl.
     setRouteLoaders(requestEv, routeLoaders);
diff --git a/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers.unit.ts b/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers.unit.ts
index de695bf3da9..62e4cad56dc 100644
--- a/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers.unit.ts
+++ b/packages/qwik-router/src/middleware/request-handler/resolve-request-handlers.unit.ts
@@ -498,6 +498,37 @@ describe('resolve-request-handler', () => {
       expect(background).toHaveBeenCalledTimes(1);
     });
 
+    it('scopes ancestor loader params to their matched path', async () => {
+      const previousStrictLoaders = globalThis.__STRICT_LOADERS__;
+      globalThis.__STRICT_LOADERS__ = true;
+      try {
+        const layoutLoader = vi.fn(() => 'layout');
+        const route = pageRouteWithLoaders(makeLoader('layout-loader', layoutLoader));
+        Object.assign(route, {
+          $routeName$: '/[tenantSlug]/agents/',
+          $params$: { tenantSlug: 'acme' },
+          $loaderPaths$: { 'layout-loader': '/acme/' },
+          $loaderParams$: { 'layout-loader': { tenantSlug: 'acme' } },
+        });
+        const handlers = resolveRequestHandlers(undefined, route, 'GET', true, exitRender());
+        const requestEv = createRequestEvent(
+          createMockServerRequestEvent('http://localhost:3000/acme/agents/'),
+          route,
+          handlers,
+          '/',
+          vi.fn()
+        );
+
+        await requestEv.next();
+
+        expect(layoutLoader).toHaveBeenCalledWith(
+          expect.objectContaining({ params: { tenantSlug: 'acme' } })
+        );
+      } finally {
+        globalThis.__STRICT_LOADERS__ = previousStrictLoaders;
+      }
+    });
+
     it('does not await blockSSR:false loaders before render', async () => {
       let release!: () => void;
       const gate = new Promise<string>((resolve) => (release = () => resolve('late')));
diff --git a/packages/qwik-router/src/runtime/src/route-loaders.ts b/packages/qwik-router/src/runtime/src/route-loaders.ts
index 8685a80fd7b..1207d0d2609 100644
--- a/packages/qwik-router/src/runtime/src/route-loaders.ts
+++ b/packages/qwik-router/src/runtime/src/route-loaders.ts
@@ -41,6 +41,7 @@ import type {
   LoaderConstructorQRL,
   LoaderInternal,
   LoaderOptions,
+  PathParams,
   RequestEvent,
   RequestEventLoader,
   RouteNavigate,
@@ -118,12 +119,14 @@ const wrapWithAbort = <T>(promise: Promise<T>, signal: AbortSignal): Promise<T>
  * a store that gets updated on navigation.
  *
  * - `loaderPaths`: loader ID → fetch path (the longest route path for that loader)
+ * - `loaderParams`: loader ID → params resolved at the loader path
  * - `pagePathname` / `pageSearch`: client-only navigation state used for loader invalidation and
  *   q-loader fetches. They are intentionally omitted from SSR state and fall back to `location`
  *   until the first SPA navigation.
  */
 export type RouteLoaderCtx = {
   loaderPaths: Record<string, string | undefined>;
+  loaderParams: Record<string, PathParams | undefined>;
   pagePathname?: string;
   pageSearch?: string;
   /** SPA navigation function. Client-only and intentionally omitted from SSR state. */
@@ -555,6 +558,7 @@ export function getRouteLoaderCtx(requestEv: RequestEventBase): RouteLoaderCtx {
   if (!ctx) {
     ctx = {
       loaderPaths: {},
+      loaderParams: {},
     };
     requestEv.sharedMap.set(REQUEST_LOADER_PATHS_STORE, ctx);
   }
@@ -772,9 +776,12 @@ export const getLoaderRequestEvent = (
   }
 
   const url = new URL(rootRequestEv.url);
+  const routeLoaderCtx = getRouteLoaderCtx(rootRequestEv);
   const pathname = globalThis.__STRICT_LOADERS__
-    ? getRouteLoaderCtx(rootRequestEv).loaderPaths[loader.__id] || rootRequestEv.url.pathname
+    ? routeLoaderCtx.loaderPaths[loader.__id] || rootRequestEv.url.pathname
     : rootRequestEv.url.pathname;
+  const scopedParams =
+    pathname === rootRequestEv.url.pathname ? {} : routeLoaderCtx.loaderParams[loader.__id] || {};
   const filteredSearch = loader.__search
     ? filterSearchParams(url.searchParams, loader.__search)
     : rootRequestEv.url.search;
@@ -800,7 +807,7 @@ export const getLoaderRequestEvent = (
         enumerable: true,
       },
       params: {
-        value: {},
+        value: scopedParams,
         enumerable: true,
       },
       pathname: {
diff --git a/packages/qwik-router/src/runtime/src/route-loaders.unit.ts b/packages/qwik-router/src/runtime/src/route-loaders.unit.ts
index 62ca50c9995..db566a4818d 100644
--- a/packages/qwik-router/src/runtime/src/route-loaders.unit.ts
+++ b/packages/qwik-router/src/runtime/src/route-loaders.unit.ts
@@ -15,7 +15,7 @@ import type { LoaderInternal } from './types';
 describe('route loader execution', () => {
   it('stores an uninitialized resume marker for never loaders', () => {
     const state = {} as RouteLoaderState;
-    const routeLoaderCtx = { loaderPaths: {} };
+    const routeLoaderCtx = { loaderPaths: {}, loaderParams: {} };
     const neverLoader = createLoader('never-loader', async () => undefined);
     const alwaysLoader = createLoader('always-loader', async () => undefined, 'always');
 
@@ -31,7 +31,7 @@ describe('route loader execution', () => {
 
   it('registers immutable loaders so nav-wide invalidation skips them', () => {
     const state = {} as RouteLoaderState;
-    const routeLoaderCtx = { loaderPaths: {} };
+    const routeLoaderCtx = { loaderPaths: {}, loaderParams: {} };
     const immutable = routeLoaderQrl(createQrl('immutable-loader'), {
       cacheControl: 'immutable',
     }) as LoaderInternal;
@@ -46,7 +46,7 @@ describe('route loader execution', () => {
 
   it('invalidates loader signals on nav, skipping resumed values and immutable loaders', () => {
     const state = {} as RouteLoaderState;
-    const routeLoaderCtx = { loaderPaths: {} };
+    const routeLoaderCtx = { loaderPaths: {}, loaderParams: {} };
     const immutable = routeLoaderQrl(createQrl('nav-immutable-loader'), {
       cacheControl: 'immutable',
     }) as LoaderInternal;
diff --git a/packages/qwik-router/src/runtime/src/routing.ts b/packages/qwik-router/src/runtime/src/routing.ts
index 0d1e38ff1c6..b5228a2df50 100644
--- a/packages/qwik-router/src/runtime/src/routing.ts
+++ b/packages/qwik-router/src/runtime/src/routing.ts
@@ -31,6 +31,7 @@ export const loadRoute = async (
     routeBundleNames,
     loaderHashes,
     loaderPathsByHash,
+    loaderParamsByHash,
     menuLoader,
     errorLoader,
   } = result;
@@ -72,6 +73,7 @@ export const loadRoute = async (
     $errorLoader$: errorLoader,
     $loaders$: loaderHashes,
     $loaderPaths$: loaderPathsByHash,
+    $loaderParams$: loaderParamsByHash,
   };
 };
 
@@ -206,7 +208,9 @@ function collectNodeMeta(
   menuLoaderRef: { v: MenuModuleLoader | undefined },
   loaderHashes?: string[],
   loaderPathsByHash?: Record<string, string>,
-  matchedPathname = '/'
+  matchedPathname = '/',
+  loaderParamsByHash?: Record<string, PathParams>,
+  matchedParams: PathParams = {}
 ) {
   for (let j = 0; j < groups.length; j++) {
     const g = groups[j];
@@ -219,6 +223,9 @@ function collectNodeMeta(
         for (let i = 0; i < g._R.length; i++) {
           const hash = g._R[i];
           loaderPathsByHash[hash] = matchedPathname;
+          if (loaderParamsByHash) {
+            loaderParamsByHash[hash] = matchedParams;
+          }
         }
       }
     }
@@ -243,6 +250,9 @@ function collectNodeMeta(
       for (let i = 0; i < node._R.length; i++) {
         const hash = node._R[i];
         loaderPathsByHash[hash] = matchedPathname;
+        if (loaderParamsByHash) {
+          loaderParamsByHash[hash] = matchedParams;
+        }
       }
     }
   }
@@ -477,6 +487,7 @@ function matchRouteTree(
   routeBundleNames: string[] | undefined;
   loaderHashes: string[] | undefined;
   loaderPathsByHash: Record<string, string> | undefined;
+  loaderParamsByHash: Record<string, PathParams> | undefined;
   menuLoader: MenuModuleLoader | undefined;
   /** The nearest _E (error.tsx) boundary's chain to render on a thrown error (in its layouts). */
   errorLoader: ModuleLoader[] | undefined;
@@ -487,6 +498,7 @@ function matchRouteTree(
   const layouts: ModuleLoader[] = [];
   const loaderHashes: string[] = [];
   const loaderPathsByHash: Record<string, string> = {};
+  const loaderParamsByHash: Record<string, PathParams> = {};
   const errorLoaderRef: BoundaryRef = { v: undefined, layouts: [] };
   const notFoundLoaderRef: BoundaryRef = { v: undefined, layouts: [] };
   const menuLoaderRef: { v: MenuModuleLoader | undefined } = { v: undefined };
@@ -503,7 +515,9 @@ function matchRouteTree(
     notFoundLoaderRef,
     menuLoaderRef,
     loaderHashes,
-    loaderPathsByHash
+    loaderPathsByHash,
+    '/',
+    loaderParamsByHash
   );
   if (root._M) {
     groupNodes.push({ node: root, depth: layouts.length });
@@ -528,6 +542,7 @@ function matchRouteTree(
         params: PathParams;
         layouts: ModuleLoader[];
         loaderPathsByHash: Record<string, string>;
+        loaderParamsByHash: Record<string, PathParams>;
         errorLoader: ContentModuleLoader | ModuleLoader[] | undefined;
         errorLayouts: ModuleLoader[];
         notFoundLoader: ContentModuleLoader | ModuleLoader[] | undefined;
@@ -561,6 +576,7 @@ function matchRouteTree(
         params: { ...params },
         layouts: [...layouts],
         loaderPathsByHash: { ...loaderPathsByHash },
+        loaderParamsByHash: { ...loaderParamsByHash },
         errorLoader: errorLoaderRef.v,
         errorLayouts: errorLoaderRef.layouts,
         notFoundLoader: notFoundLoaderRef.v,
@@ -586,7 +602,9 @@ function matchRouteTree(
       menuLoaderRef,
       loaderHashes,
       loaderPathsByHash,
-      matchedPathname
+      matchedPathname,
+      loaderParamsByHash,
+      { ...params }
     );
     if (node._M) {
       groupNodes.push({ node, depth: layouts.length });
@@ -611,7 +629,9 @@ function matchRouteTree(
           menuLoaderRef,
           loaderHashes,
           loaderPathsByHash,
-          pathname
+          pathname,
+          loaderParamsByHash,
+          { ...params }
         );
         node = indexResult.target;
       }
@@ -635,7 +655,9 @@ function matchRouteTree(
           menuLoaderRef,
           loaderHashes,
           loaderPathsByHash,
-          pathname
+          pathname,
+          loaderParamsByHash,
+          { ...params }
         );
         node = next;
       }
@@ -654,6 +676,7 @@ function matchRouteTree(
     const fbRouteParts = [...fb.routeParts, `[...${fb.paramName}]`];
     const fbLayouts = [...fb.layouts];
     const fbLoaderPathsByHash = { ...fb.loaderPathsByHash };
+    const fbLoaderParamsByHash = { ...fb.loaderParamsByHash };
     const fbErrorRef: BoundaryRef = { v: fb.errorLoader, layouts: fb.errorLayouts };
     const fbNotFoundRef: BoundaryRef = { v: fb.notFoundLoader, layouts: fb.notFoundLayouts };
     const fbMenuRef: { v: MenuModuleLoader | undefined } = { v: fb.menuLoader };
@@ -668,7 +691,9 @@ function matchRouteTree(
       fbMenuRef,
       fbLoaderHashes,
       fbLoaderPathsByHash,
-      pathname
+      pathname,
+      fbLoaderParamsByHash,
+      fbParams
     );
 
     const fbLoaders = resolveLoaders(root, fb.aNode, fbLayouts);
@@ -682,6 +707,8 @@ function matchRouteTree(
         loaderHashes: fbLoaderHashes.length > 0 ? fbLoaderHashes : undefined,
         loaderPathsByHash:
           Object.keys(fbLoaderPathsByHash).length > 0 ? fbLoaderPathsByHash : undefined,
+        loaderParamsByHash:
+          Object.keys(fbLoaderParamsByHash).length > 0 ? fbLoaderParamsByHash : undefined,
         menuLoader: fbMenuRef.v,
         errorLoader: boundaryChain(fbErrorRef),
       };
@@ -737,6 +764,7 @@ function matchRouteTree(
       routeBundleNames: undefined,
       loaderHashes: undefined,
       loaderPathsByHash: undefined,
+      loaderParamsByHash: undefined,
       menuLoader: menuLoaderRef.v,
       errorLoader: boundaryChain(errorLoaderRef),
     };
@@ -749,6 +777,7 @@ function matchRouteTree(
     for (let i = 0; i < node._R.length; i++) {
       const hash = node._R[i];
       loaderPathsByHash[hash] = matchedPathname;
+      loaderParamsByHash[hash] = { ...params };
     }
   }
 
@@ -760,6 +789,7 @@ function matchRouteTree(
     routeBundleNames: node._B as string[] | undefined,
     loaderHashes: loaderHashes.length > 0 ? loaderHashes : undefined,
     loaderPathsByHash: Object.keys(loaderPathsByHash).length > 0 ? loaderPathsByHash : undefined,
+    loaderParamsByHash: Object.keys(loaderParamsByHash).length > 0 ? loaderParamsByHash : undefined,
     menuLoader: menuLoaderRef.v,
     errorLoader: boundaryChain(errorLoaderRef),
   };
diff --git a/packages/qwik-router/src/runtime/src/routing.unit.ts b/packages/qwik-router/src/runtime/src/routing.unit.ts
index 0c50bd3a750..2a7b03c5a68 100644
--- a/packages/qwik-router/src/runtime/src/routing.unit.ts
+++ b/packages/qwik-router/src/runtime/src/routing.unit.ts
@@ -247,6 +247,36 @@ test('loadRoute — loader paths are replaced by deeper matches', async () => {
   });
 });
 
+test('loadRoute — loader params match each loader path', async () => {
+  const routes: RouteData = {
+    _R: ['root-loader'],
+    _W: {
+      _P: 'tenantSlug',
+      _R: ['tenant-loader'],
+      agents: {
+        _W: {
+          _P: 'agentId',
+          _R: ['agent-loader'],
+          view: {
+            _R: ['page-loader'],
+            _I: makeLoader(),
+          },
+        },
+      },
+    },
+  };
+
+  const result = await loadRoute(routes, false, '/acme/agents/42/view');
+
+  assert.isFalse(result.$notFound$);
+  assert.deepEqual(result.$loaderParams$, {
+    'root-loader': {},
+    'tenant-loader': { tenantSlug: 'acme' },
+    'agent-loader': { tenantSlug: 'acme', agentId: '42' },
+    'page-loader': { tenantSlug: 'acme', agentId: '42' },
+  });
+});
+
 test('loadRoute — miss renders the nearest _4 inside gathered layouts', async () => {
   const rootLayout = { default: () => 'layout' };
   const notFound = { default: () => 'not-found' };
diff --git a/packages/qwik-router/src/runtime/src/types.ts b/packages/qwik-router/src/runtime/src/types.ts
index 2a033d86a3d..591caf14bc6 100644
--- a/packages/qwik-router/src/runtime/src/types.ts
+++ b/packages/qwik-router/src/runtime/src/types.ts
@@ -446,6 +446,8 @@ export interface LoadedRoute {
   $loaders$?: string[];
   /** Runtime-only mapping of routeLoader$ hashes to the matched pathname used for q-loader fetches */
   $loaderPaths$?: Record<string, string>;
+  /** Runtime-only mapping of routeLoader$ hashes to params matched at their loader path */
+  $loaderParams$?: Record<string, PathParams>;
 }
 
 export interface EndpointResponse {