diff --git a/packages/api/src/router/incident.ts b/packages/api/src/router/incident.ts
index 73368577..4745cac3 100644
--- a/packages/api/src/router/incident.ts
+++ b/packages/api/src/router/incident.ts
@@ -1,5 +1,6 @@
 import { Events } from "@openstatus/analytics";
 import { incidentStatus } from "@openstatus/db/src/schema/incidents/constants";
+import { sendIncidentCommander } from "@openstatus/emails";
 import {
   AddIncidentNoteInput,
   BindIncidentSlackChannelInput,
@@ -31,6 +32,37 @@ import { z } from "zod";
 import { toServiceCtx, toTRPCError } from "../service-adapter";
 import { createTRPCRouter, protectedProcedure } from "../trpc";
 
+const DASHBOARD_URL =
+  process.env.NODE_ENV === "production"
+    ? "https://app.openstatus.dev"
+    : "http://localhost:3001";
+
+/** Best effort: a failed email never fails the mutation that assigned them. */
+async function notifyCommander(
+  ctx: Parameters<typeof toServiceCtx>[0],
+  incidentId: number,
+) {
+  try {
+    const row = await getIncident({
+      ctx: toServiceCtx(ctx),
+      input: { id: incidentId },
+    });
+    const commander = row?.commander;
+    if (!row || !commander?.email || commander.id === ctx.user.id) return;
+    await sendIncidentCommander({
+      to: commander.email,
+      incidentTitle: row.title,
+      severity: row.severity,
+      workspaceName: ctx.workspace.name ?? ctx.workspace.slug,
+      assignedBy: ctx.user.name || ctx.user.email || "A teammate",
+      url: `${DASHBOARD_URL}/incidents/${row.id}`,
+      idempotencyKey: `incident-commander:${row.id}:${commander.id}:${row.updatedAt.getTime()}`,
+    });
+  } catch (err) {
+    console.warn("incident commander email failed", { incidentId, err });
+  }
+}
+
 export const incidentRouter = createTRPCRouter({
   list: protectedProcedure
     .input(
@@ -101,7 +133,9 @@ export const incidentRouter = createTRPCRouter({
     .input(DeclareIncidentInput)
     .mutation(async ({ ctx, input }) => {
       try {
-        return await declareIncident({ ctx: toServiceCtx(ctx), input });
+        const row = await declareIncident({ ctx: toServiceCtx(ctx), input });
+        if (row.commanderId !== null) await notifyCommander(ctx, row.id);
+        return row;
       } catch (err) {
         toTRPCError(err);
       }
@@ -112,7 +146,18 @@ export const incidentRouter = createTRPCRouter({
     .input(UpdateIncidentInput)
     .mutation(async ({ ctx, input }) => {
       try {
-        return await updateIncident({ ctx: toServiceCtx(ctx), input });
+        const before = await getIncident({
+          ctx: toServiceCtx(ctx),
+          input: { id: input.id },
+        });
+        const row = await updateIncident({ ctx: toServiceCtx(ctx), input });
+        if (
+          row.commanderId !== null &&
+          row.commanderId !== before?.commanderId
+        ) {
+          await notifyCommander(ctx, row.id);
+        }
+        return row;
       } catch (err) {
         toTRPCError(err);
       }
diff --git a/packages/emails/emails/incident-commander.tsx b/packages/emails/emails/incident-commander.tsx
new file mode 100644
index 00000000..abb65a53
--- /dev/null
+++ b/packages/emails/emails/incident-commander.tsx
@@ -0,0 +1,61 @@
+/** @jsxRuntime automatic @jsxImportSource react */
+
+import { Actions } from "./_components/actions";
+import { Footer } from "./_components/footer";
+import { Heading } from "./_components/heading";
+import { KeyValue } from "./_components/key-value";
+import { Layout } from "./_components/layout";
+
+export interface IncidentCommanderProps {
+  incidentTitle: string;
+  severity: "critical" | "major" | "minor";
+  workspaceName: string;
+  assignedBy: string;
+  url: string;
+}
+
+export function incidentCommanderSubject(
+  props: IncidentCommanderProps,
+): string {
+  return `You are commander of ${props.incidentTitle}`;
+}
+
+const tone = {
+  critical: "danger",
+  major: "warning",
+  minor: "info",
+} as const;
+
+const IncidentCommanderEmail = (props: IncidentCommanderProps) => {
+  return (
+    <Layout
+      preview={`${props.assignedBy} made you commander of a ${props.severity} incident.`}
+      pill={{ tone: tone[props.severity], label: `${props.severity} incident` }}
+      footer={
+        <Footer reason="You get this because you were made commander of an incident in this workspace." />
+      }
+    >
+      <Heading title={`You are commander of ${props.incidentTitle}`}>
+        {`${props.assignedBy} made you the commander of this incident in ${props.workspaceName}. You lead the response: keep the timeline current, decide when it is resolved, and close it with a postmortem.`}
+      </Heading>
+      <KeyValue
+        rows={[
+          { label: "Incident", value: props.incidentTitle },
+          { label: "Severity", value: props.severity },
+          { label: "Workspace", value: props.workspaceName },
+        ]}
+      />
+      <Actions primary={{ label: "Open incident", href: props.url }} />
+    </Layout>
+  );
+};
+
+IncidentCommanderEmail.PreviewProps = {
+  incidentTitle: "Checkout is failing",
+  severity: "critical",
+  workspaceName: "Acme",
+  assignedBy: "Max",
+  url: "https://app.openstatus.dev/incidents/1",
+} satisfies IncidentCommanderProps;
+
+export default IncidentCommanderEmail;
diff --git a/packages/emails/src/incident.tsx b/packages/emails/src/incident.tsx
new file mode 100644
index 00000000..40d96bea
--- /dev/null
+++ b/packages/emails/src/incident.tsx
@@ -0,0 +1,26 @@
+/** @jsxRuntime automatic @jsxImportSource react */
+
+import IncidentCommanderEmail, {
+  type IncidentCommanderProps,
+  incidentCommanderSubject,
+} from "../emails/incident-commander";
+import { sendEmail } from "./send";
+
+const SYSTEM_FROM = "openstatus <notifications@notifications.openstatus.dev>";
+const SUPPORT_EMAIL = "ping@openstatus.dev";
+
+export async function sendIncidentCommander(
+  req: IncidentCommanderProps & { to: string; idempotencyKey?: string },
+) {
+  const { to, idempotencyKey, ...props } = req;
+  return sendEmail(
+    {
+      from: SYSTEM_FROM,
+      reply_to: SUPPORT_EMAIL,
+      to: [to],
+      subject: incidentCommanderSubject(props),
+      react: <IncidentCommanderEmail {...props} />,
+    },
+    { idempotencyKey },
+  );
+}
diff --git a/packages/emails/src/index.ts b/packages/emails/src/index.ts
index 24220f1d..c5257906 100644
--- a/packages/emails/src/index.ts
+++ b/packages/emails/src/index.ts
@@ -27,4 +27,6 @@ export {
   stripeIdempotencyKey,
 } from "./billing";
 
+export { sendIncidentCommander } from "./incident";
+
 export { EmailClient } from "./client";
diff --git a/packages/emails/src/templates.test.tsx b/packages/emails/src/templates.test.tsx
index b56f5789..456cdc1a 100644
--- a/packages/emails/src/templates.test.tsx
+++ b/packages/emails/src/templates.test.tsx
@@ -13,6 +13,9 @@ import { renderMarkdown } from "../emails/_components/markdown";
 import { Pill } from "../emails/_components/pill";
 import { Steps } from "../emails/_components/steps";
 import { tones } from "../emails/_components/styles";
+import IncidentCommanderEmail, {
+  incidentCommanderSubject,
+} from "../emails/incident-commander";
 import MonitorAlertEmail, {
   type MonitorAlertProps,
   monitorAlertPreheader,
@@ -680,6 +683,9 @@ describe("every transactional template", () => {
     subscription: <PageSubscriptionEmail page="Acme" link="https://a.dev" />,
     magicLink: <StatusPageMagicLinkEmail page="Acme" link="https://a.dev" />,
     welcome: <WelcomeEmail trialEndsAt={new Date("2026-10-07T00:00:00Z")} />,
+    incidentCommander: (
+      <IncidentCommanderEmail {...IncidentCommanderEmail.PreviewProps} />
+    ),
   };
 
   for (const [name, element] of Object.entries(all)) {
@@ -707,3 +713,22 @@ describe("WelcomeEmail", () => {
     expect(withoutTrial).not.toContain("trial");
   });
 });
+
+describe("IncidentCommanderEmail", () => {
+  test("names the incident, the assigner and links to it", async () => {
+    const props = {
+      incidentTitle: "Checkout is failing",
+      severity: "critical" as const,
+      workspaceName: "Acme",
+      assignedBy: "Max",
+      url: "https://app.openstatus.dev/incidents/7",
+    };
+    const html = await render(<IncidentCommanderEmail {...props} />);
+    expect(html).toContain("Checkout is failing");
+    expect(html).toContain("Max made you the commander");
+    expect(html).toContain("https://app.openstatus.dev/incidents/7");
+    expect(incidentCommanderSubject(props)).toBe(
+      "You are commander of Checkout is failing",
+    );
+  });
+});