diff --git a/actions/setup/js/send_otlp_span.cjs b/actions/setup/js/send_otlp_span.cjs
index 8c077000c2..c70c04891a 100644
--- a/actions/setup/js/send_otlp_span.cjs
+++ b/actions/setup/js/send_otlp_span.cjs
@@ -496,6 +496,9 @@ async function sendJobSetupSpan(options = {}) {
   if (engineId) {
     attributes.push(buildAttr("gh-aw.engine.id", engineId));
   }
+  if (eventName) {
+    attributes.push(buildAttr("gh-aw.event_name", eventName));
+  }
 
   const resourceAttributes = [buildAttr("github.repository", repository), buildAttr("github.run_id", runId)];
   if (repository && runId) {
@@ -707,6 +710,7 @@ async function sendJobConclusionSpan(spanName, options = {}) {
   if (jobName) attributes.push(buildAttr("gh-aw.job.name", jobName));
   if (engineId) attributes.push(buildAttr("gh-aw.engine.id", engineId));
   if (model) attributes.push(buildAttr("gh-aw.model", model));
+  if (eventName) attributes.push(buildAttr("gh-aw.event_name", eventName));
   attributes.push(buildAttr("gh-aw.staged", staged));
   if (!isNaN(effectiveTokens) && effectiveTokens > 0) {
     attributes.push(buildAttr("gh-aw.effective_tokens", effectiveTokens));
diff --git a/actions/setup/js/send_otlp_span.test.cjs b/actions/setup/js/send_otlp_span.test.cjs
index 3b7505ce47..c2b47aed9b 100644
--- a/actions/setup/js/send_otlp_span.test.cjs
+++ b/actions/setup/js/send_otlp_span.test.cjs
@@ -1047,6 +1047,34 @@ describe("sendJobSetupSpan", () => {
     expect(resourceKeys).not.toContain("github.event_name");
   });
 
+  it("includes gh-aw.event_name as span attribute when GITHUB_EVENT_NAME is set", 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";
+    process.env.GITHUB_EVENT_NAME = "workflow_dispatch";
+
+    await sendJobSetupSpan();
+
+    const body = JSON.parse(mockFetch.mock.calls[0][1].body);
+    const span = body.resourceSpans[0].scopeSpans[0].spans[0];
+    expect(span.attributes).toContainEqual({ key: "gh-aw.event_name", value: { stringValue: "workflow_dispatch" } });
+  });
+
+  it("omits gh-aw.event_name span attribute when GITHUB_EVENT_NAME is not set", 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 span = body.resourceSpans[0].scopeSpans[0].spans[0];
+    const keys = span.attributes.map(a => a.key);
+    expect(keys).not.toContain("gh-aw.event_name");
+  });
+
   it("includes github.ref as resource attribute when GITHUB_REF is set", async () => {
     const mockFetch = vi.fn().mockResolvedValue({ ok: true, status: 200, statusText: "OK" });
     vi.stubGlobal("fetch", mockFetch);
@@ -1578,6 +1606,34 @@ describe("sendJobConclusionSpan", () => {
     expect(resourceKeys).not.toContain("github.event_name");
   });
 
+  it("includes gh-aw.event_name as span attribute when GITHUB_EVENT_NAME is set", 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";
+    process.env.GITHUB_EVENT_NAME = "pull_request";
+
+    await sendJobConclusionSpan("gh-aw.job.conclusion");
+
+    const body = JSON.parse(mockFetch.mock.calls[0][1].body);
+    const span = body.resourceSpans[0].scopeSpans[0].spans[0];
+    expect(span.attributes).toContainEqual({ key: "gh-aw.event_name", value: { stringValue: "pull_request" } });
+  });
+
+  it("omits gh-aw.event_name span attribute when GITHUB_EVENT_NAME is not set", 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 sendJobConclusionSpan("gh-aw.job.conclusion");
+
+    const body = JSON.parse(mockFetch.mock.calls[0][1].body);
+    const span = body.resourceSpans[0].scopeSpans[0].spans[0];
+    const keys = span.attributes.map(a => a.key);
+    expect(keys).not.toContain("gh-aw.event_name");
+  });
+
   it("includes github.ref as resource attribute when GITHUB_REF is set", async () => {
     const mockFetch = vi.fn().mockResolvedValue({ ok: true, status: 200, statusText: "OK" });
     vi.stubGlobal("fetch", mockFetch);