diff --git a/actions/setup/js/send_otlp_span.cjs b/actions/setup/js/send_otlp_span.cjs
index e174f892a4e..bbcda664338 100644
--- a/actions/setup/js/send_otlp_span.cjs
+++ b/actions/setup/js/send_otlp_span.cjs
@@ -363,6 +363,7 @@ async function sendJobSetupSpan(options = {}) {
   const awInfo = readJSONIfExists("/tmp/gh-aw/aw_info.json") || {};
   const rawContextTraceId = typeof awInfo.context?.otel_trace_id === "string" ? awInfo.context.otel_trace_id.trim().toLowerCase() : "";
   const contextTraceId = isValidTraceId(rawContextTraceId) ? rawContextTraceId : "";
+  const staged = awInfo.staged === true;
 
   const traceId = optionsTraceId || inputTraceId || contextTraceId || generateTraceId();
 
@@ -410,6 +411,7 @@ async function sendJobSetupSpan(options = {}) {
   if (eventName) {
     resourceAttributes.push(buildAttr("github.event_name", eventName));
   }
+  resourceAttributes.push(buildAttr("deployment.environment", staged ? "staging" : "production"));
 
   const payload = buildOTLPPayload({
     traceId,
diff --git a/actions/setup/js/send_otlp_span.test.cjs b/actions/setup/js/send_otlp_span.test.cjs
index 14852f090a7..f473b228554 100644
--- a/actions/setup/js/send_otlp_span.test.cjs
+++ b/actions/setup/js/send_otlp_span.test.cjs
@@ -1012,6 +1012,73 @@ describe("sendJobSetupSpan", () => {
     const keys = span.attributes.map(a => a.key);
     expect(keys).not.toContain("gh-aw.engine.id");
   });
+
+  describe("staged / deployment.environment", () => {
+    let readFileSpy;
+
+    beforeEach(() => {
+      readFileSpy = vi.spyOn(fs, "readFileSync").mockImplementation(() => {
+        throw Object.assign(new Error("ENOENT"), { code: "ENOENT" });
+      });
+    });
+
+    afterEach(() => {
+      readFileSpy.mockRestore();
+    });
+
+    it("sets deployment.environment=production when aw_info.json is absent", async () => {
+      const mockFetch = vi.fn().mockResolvedValue({ ok: true, status: 200, statusText: "OK" });
+      vi.stubGlobal("fetch", mockFetch);
+
+      process.env.OTEL_EXPORTER_OTLP_ENDPOINT = "https://traces.example.com";
+
+      await sendJobSetupSpan();
+
+      const body = JSON.parse(mockFetch.mock.calls[0][1].body);
+      const resourceAttrs = body.resourceSpans[0].resource.attributes;
+      expect(resourceAttrs).toContainEqual({ key: "deployment.environment", value: { stringValue: "production" } });
+    });
+
+    it("sets deployment.environment=staging when awInfo.staged=true", async () => {
+      const mockFetch = vi.fn().mockResolvedValue({ ok: true, status: 200, statusText: "OK" });
+      vi.stubGlobal("fetch", mockFetch);
+
+      process.env.OTEL_EXPORTER_OTLP_ENDPOINT = "https://traces.example.com";
+
+      readFileSpy.mockImplementation(filePath => {
+        if (filePath === "/tmp/gh-aw/aw_info.json") {
+          return JSON.stringify({ staged: true });
+        }
+        throw Object.assign(new Error("ENOENT"), { code: "ENOENT" });
+      });
+
+      await sendJobSetupSpan();
+
+      const body = JSON.parse(mockFetch.mock.calls[0][1].body);
+      const resourceAttrs = body.resourceSpans[0].resource.attributes;
+      expect(resourceAttrs).toContainEqual({ key: "deployment.environment", value: { stringValue: "staging" } });
+    });
+
+    it("sets deployment.environment=production when awInfo.staged=false", async () => {
+      const mockFetch = vi.fn().mockResolvedValue({ ok: true, status: 200, statusText: "OK" });
+      vi.stubGlobal("fetch", mockFetch);
+
+      process.env.OTEL_EXPORTER_OTLP_ENDPOINT = "https://traces.example.com";
+
+      readFileSpy.mockImplementation(filePath => {
+        if (filePath === "/tmp/gh-aw/aw_info.json") {
+          return JSON.stringify({ staged: false });
+        }
+        throw Object.assign(new Error("ENOENT"), { code: "ENOENT" });
+      });
+
+      await sendJobSetupSpan();
+
+      const body = JSON.parse(mockFetch.mock.calls[0][1].body);
+      const resourceAttrs = body.resourceSpans[0].resource.attributes;
+      expect(resourceAttrs).toContainEqual({ key: "deployment.environment", value: { stringValue: "production" } });
+    });
+  });
 });
 
 // ---------------------------------------------------------------------------