diff --git a/.changeset/quiet-mice-invent.md b/.changeset/quiet-mice-invent.md
new file mode 100644
index 00000000000..bf601aaad60
--- /dev/null
+++ b/.changeset/quiet-mice-invent.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/lit-query': patch
+---
+
+feat: add `DataTag` branding to `infiniteQueryOptions` queryKey so `setQueryData`/`getQueryData` infer the `InfiniteData` type, matching `queryOptions` and the other adapters
diff --git a/packages/lit-query/src/infiniteQueryOptions.ts b/packages/lit-query/src/infiniteQueryOptions.ts
index f4bc8851ebe..7f31a939883 100644
--- a/packages/lit-query/src/infiniteQueryOptions.ts
+++ b/packages/lit-query/src/infiniteQueryOptions.ts
@@ -1,4 +1,5 @@
 import type {
+  DataTag,
   DefaultError,
   InfiniteData,
   InfiniteQueryObserverOptions,
@@ -43,6 +44,8 @@ export function infiniteQueryOptions<
   TData,
   TQueryKey,
   TPageParam
-> {
+> & {
+  queryKey: DataTag<TQueryKey, InfiniteData<TQueryFnData>, TError>
+} {
   return options
 }
diff --git a/packages/lit-query/src/tests/type-inference.test.ts b/packages/lit-query/src/tests/type-inference.test.ts
index e8c6c3c525d..42d9d1578d1 100644
--- a/packages/lit-query/src/tests/type-inference.test.ts
+++ b/packages/lit-query/src/tests/type-inference.test.ts
@@ -2,6 +2,7 @@ import {
   dataTagSymbol,
   QueryClient,
   type DefinedQueryObserverResult,
+  type InfiniteData,
   type QueryObserverResult,
 } from '@tanstack/query-core'
 import { describe, expectTypeOf, it } from 'vitest'
@@ -206,5 +207,26 @@ describe('type inference', () => {
     expectTypeOf(infinite().data?.pages).toEqualTypeOf<
       Array<{ page: number }> | undefined
     >()
+
+    const infiniteOpts = infiniteQueryOptions({
+      queryKey: ['type-inference', 'infinite-options'] as const,
+      initialPageParam: 0,
+      queryFn: async () => ({ page: 2 }),
+      getNextPageParam: (lastPage) => lastPage.page + 1,
+    })
+    expectTypeOf(infiniteOpts.queryKey[dataTagSymbol]).toEqualTypeOf<
+      InfiniteData<{ page: number }>
+    >()
+    const cachedInfinite = client.getQueryData(infiniteOpts.queryKey)
+    expectTypeOf(cachedInfinite).toEqualTypeOf<
+      InfiniteData<{ page: number }> | undefined
+    >()
+    const updatedInfinite = client.setQueryData(infiniteOpts.queryKey, {
+      pages: [{ page: 3 }],
+      pageParams: [0],
+    })
+    expectTypeOf(updatedInfinite).toEqualTypeOf<
+      InfiniteData<{ page: number }> | undefined
+    >()
   })
 })