diff --git a/actions/setup/js/resolve_pr_review_thread.cjs b/actions/setup/js/resolve_pr_review_thread.cjs
index b629aec598c..e4f2bd33a97 100644
--- a/actions/setup/js/resolve_pr_review_thread.cjs
+++ b/actions/setup/js/resolve_pr_review_thread.cjs
@@ -250,6 +250,57 @@ function isIntegrationAccessError(error) {
   return messages.some(message => message.toLowerCase().includes(integrationErrorFragment));
 }
 
+/**
+ * Check whether an error indicates the referenced GraphQL node no longer exists.
+ * Review thread node IDs can become stale between the agent turn and the safe-outputs
+ * replay (thread already resolved, deleted, or superseded), which surfaces as a
+ * "Could not resolve to a node" or "Not Found" error. These are treated as skippable.
+ * @param {unknown} error
+ * @returns {boolean}
+ */
+function isMissingNodeError(error) {
+  /** @type {string[]} */
+  const messages = [getErrorMessage(error)];
+  /** @type {Array<{type?: unknown, message?: unknown, path?: unknown}>} */
+  const graphQLErrors = [];
+
+  if (error && typeof error === "object" && "errors" in error && Array.isArray(error.errors)) {
+    for (const graphQLError of error.errors) {
+      graphQLErrors.push(graphQLError);
+      if (typeof graphQLError?.message === "string") {
+        messages.push(graphQLError.message);
+      }
+    }
+  }
+
+  const hasNodeScopedNotFoundType = graphQLErrors.some(graphQLError => {
+    if (typeof graphQLError?.type !== "string" || graphQLError.type.toUpperCase() !== "NOT_FOUND") {
+      return false;
+    }
+    const hasNodeScopedMessage = typeof graphQLError?.message === "string" && graphQLError.message.toLowerCase().includes("could not resolve to a node");
+    const hasNodeScopedPath =
+      Array.isArray(graphQLError?.path) &&
+      graphQLError.path.some(pathPart => {
+        if (typeof pathPart !== "string") return false;
+        const normalized = pathPart.toLowerCase();
+        // GraphQL paths for stale-thread mutation failures are rooted at "resolveReviewThread".
+        return normalized === "node" || normalized === "resolvereviewthread";
+      });
+    return hasNodeScopedMessage || hasNodeScopedPath;
+  });
+  if (hasNodeScopedNotFoundType) {
+    return true;
+  }
+
+  return messages.some(message => {
+    const normalized = message.trim().toLowerCase();
+    // Match the stale-node GraphQL error, or Octokit's bare "Not Found" 404 message.
+    // Deliberately avoid a loose "not found" substring match so unrelated errors
+    // (e.g. "Repository not found") still surface as real failures.
+    return normalized.includes("could not resolve to a node") || normalized === "not found";
+  });
+}
+
 /**
  * Main handler factory for resolve_pull_request_review_thread
  * Returns a message handler function that processes individual resolve messages.
@@ -323,7 +374,22 @@ async function main(config = {}) {
       }
 
       // Look up the thread's PR number and repository
-      const threadInfo = await getThreadPullRequestInfo(githubClient, threadId);
+      /** @type {Awaited<ReturnType<typeof getThreadPullRequestInfo>>} */
+      let threadInfo;
+      try {
+        threadInfo = await getThreadPullRequestInfo(githubClient, threadId);
+      } catch (error) {
+        if (isMissingNodeError(error)) {
+          core.info(`Review thread ${threadId} could not be resolved (${getErrorMessage(error)}) — already resolved or stale; skipping`);
+          return {
+            success: true,
+            thread_id: threadId,
+            is_resolved: true,
+            skipped: true,
+          };
+        }
+        throw error;
+      }
       if (threadInfo.status === "missing") {
         core.info(`Review thread ${threadId} not found — already resolved or stale; skipping`);
         return {
@@ -478,6 +544,15 @@ async function main(config = {}) {
       try {
         resolveResult = await resolveReviewThreadAPI(githubClient, resolvedThreadId);
       } catch (error) {
+        if (isMissingNodeError(error)) {
+          core.info(`Review thread ${resolvedThreadId} could not be resolved (${getErrorMessage(error)}) — already resolved or stale; skipping`);
+          return {
+            success: true,
+            thread_id: resolvedThreadId,
+            is_resolved: true,
+            skipped: true,
+          };
+        }
         if (isIntegrationAccessError(error)) {
           const warningMessage =
             `Skipping resolve_pull_request_review_thread for ${resolvedThreadId}: configuration mismatch ` +
diff --git a/actions/setup/js/resolve_pr_review_thread.test.cjs b/actions/setup/js/resolve_pr_review_thread.test.cjs
index 4cd8294603a..9f6f1f5e79c 100644
--- a/actions/setup/js/resolve_pr_review_thread.test.cjs
+++ b/actions/setup/js/resolve_pr_review_thread.test.cjs
@@ -154,6 +154,104 @@ describe("resolve_pr_review_thread", () => {
     expect(mockGraphql).toHaveBeenCalledTimes(1);
   });
 
+  it("should succeed as a no-op when the lookup throws a stale-node GraphQL error", async () => {
+    mockGraphql.mockImplementation(() => {
+      const error = new Error("Request failed");
+      error.errors = [{ type: "NOT_FOUND", message: "Could not resolve to a node with the global id of 'PRRT_kwDOPc1QR87fJc0o'" }];
+      return Promise.reject(error);
+    });
+
+    const { main } = require("./resolve_pr_review_thread.cjs");
+    const freshHandler = await main({ max: 10 });
+
+    const result = await freshHandler({ type: "resolve_pull_request_review_thread", thread_id: "PRRT_kwDOPc1QR87fJc0o" }, {});
+
+    expect(result.success).toBe(true);
+    expect(result.skipped).toBe(true);
+    expect(result.is_resolved).toBe(true);
+    expect(mockCore.error).not.toHaveBeenCalled();
+  });
+
+  it("should succeed as a no-op when the lookup throws a plain Not Found error", async () => {
+    mockGraphql.mockImplementation(() => Promise.reject(new Error("Not Found")));
+
+    const { main } = require("./resolve_pr_review_thread.cjs");
+    const freshHandler = await main({ max: 10 });
+
+    const result = await freshHandler({ type: "resolve_pull_request_review_thread", thread_id: "PRRT_stale" }, {});
+
+    expect(result.success).toBe(true);
+    expect(result.skipped).toBe(true);
+    expect(mockCore.error).not.toHaveBeenCalled();
+  });
+
+  it("should succeed as a no-op when the resolve mutation reports a stale node", async () => {
+    mockGraphql.mockImplementation(query => {
+      if (query.includes("resolveReviewThread")) {
+        const error = new Error("Could not resolve to a node with the global id of 'PRRT_kwDOABCD123456'");
+        return Promise.reject(error);
+      }
+      return Promise.resolve({
+        node: {
+          __typename: "PullRequestReviewThread",
+          id: "PRRT_kwDOABCD123456",
+          isResolved: false,
+          pullRequest: { number: 42, repository: { nameWithOwner: "test-owner/test-repo" } },
+        },
+      });
+    });
+
+    const { main } = require("./resolve_pr_review_thread.cjs");
+    const freshHandler = await main({ max: 10 });
+
+    const result = await freshHandler({ type: "resolve_pull_request_review_thread", thread_id: "PRRT_kwDOABCD123456" }, {});
+
+    expect(result.success).toBe(true);
+    expect(result.skipped).toBe(true);
+    expect(result.is_resolved).toBe(true);
+    expect(mockCore.error).not.toHaveBeenCalled();
+  });
+
+  it("should still fail for unrelated lookup errors", async () => {
+    mockGraphql.mockImplementation(() => Promise.reject(new Error("Internal server error")));
+
+    const { main } = require("./resolve_pr_review_thread.cjs");
+    const freshHandler = await main({ max: 10 });
+
+    const result = await freshHandler({ type: "resolve_pull_request_review_thread", thread_id: "PRRT_kwDOABCD123456" }, {});
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Internal server error");
+  });
+
+  it("should still fail for unrelated 'not found' errors such as a missing repository", async () => {
+    mockGraphql.mockImplementation(() => Promise.reject(new Error("Repository not found")));
+
+    const { main } = require("./resolve_pr_review_thread.cjs");
+    const freshHandler = await main({ max: 10 });
+
+    const result = await freshHandler({ type: "resolve_pull_request_review_thread", thread_id: "PRRT_kwDOABCD123456" }, {});
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Repository not found");
+  });
+
+  it("should still fail for structured NOT_FOUND errors unrelated to stale thread nodes", async () => {
+    mockGraphql.mockImplementation(() => {
+      const error = new Error("Repository not found");
+      error.errors = [{ type: "NOT_FOUND", message: "Repository not found", path: ["repository"] }];
+      return Promise.reject(error);
+    });
+
+    const { main } = require("./resolve_pr_review_thread.cjs");
+    const freshHandler = await main({ max: 10 });
+
+    const result = await freshHandler({ type: "resolve_pull_request_review_thread", thread_id: "PRRT_kwDOABCD123456" }, {});
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Repository not found");
+  });
+
   it("should resolve a review comment node ID by finding its parent thread", async () => {
     mockGraphql.mockImplementation(query => {
       if (query.includes("resolveReviewThread")) {
@@ -582,7 +680,7 @@ describe("resolve_pr_review_thread", () => {
   });
 
   it("should handle API errors gracefully", async () => {
-    mockGraphql.mockRejectedValue(new Error("Could not resolve. Thread not found."));
+    mockGraphql.mockRejectedValue(new Error("Internal server error while loading thread"));
 
     const message = {
       type: "resolve_pull_request_review_thread",
@@ -592,7 +690,7 @@ describe("resolve_pr_review_thread", () => {
     const result = await handler(message, {});
 
     expect(result.success).toBe(false);
-    expect(result.error).toContain("Could not resolve");
+    expect(result.error).toContain("Internal server error");
   });
 
   it("should soft-skip when resolve mutation returns integration access error", async () => {