diff --git a/.server-changes/clamp-run-priority.md b/.server-changes/clamp-run-priority.md
new file mode 100644
index 00000000000..c457de850ef
--- /dev/null
+++ b/.server-changes/clamp-run-priority.md
@@ -0,0 +1,6 @@
+---
+area: webapp
+type: fix
+---
+
+Triggering a run with a very large `priority` no longer fails. The priority is now capped to the highest supported value instead of erroring out.
diff --git a/apps/webapp/app/runEngine/services/triggerTask.server.ts b/apps/webapp/app/runEngine/services/triggerTask.server.ts
index ff22a479a1d..cb847f9fcb5 100644
--- a/apps/webapp/app/runEngine/services/triggerTask.server.ts
+++ b/apps/webapp/app/runEngine/services/triggerTask.server.ts
@@ -33,6 +33,7 @@ import type {
   TriggerTaskServiceResult,
 } from "../../v3/services/triggerTask.server";
 import { clampMaxDuration } from "../../v3/utils/maxDuration";
+import { clampPriorityMs } from "../../v3/utils/priority";
 import {
   type IdempotencyKeyConcern,
   type ClaimedIdempotency,
@@ -887,7 +888,9 @@ export class RunEngineTriggerTaskService {
         ? clampMaxDuration(args.body.options.maxDuration)
         : undefined,
       machine: args.body.options?.machine,
-      priorityMs: args.body.options?.priority ? args.body.options.priority * 1_000 : undefined,
+      priorityMs: args.body.options?.priority
+        ? clampPriorityMs(args.body.options.priority)
+        : undefined,
       queueTimestamp:
         args.options.queueTimestamp ??
         (args.parentRun && args.body.options?.resumeParentOnCompletion
diff --git a/apps/webapp/app/v3/utils/priority.test.ts b/apps/webapp/app/v3/utils/priority.test.ts
new file mode 100644
index 00000000000..c4feb7a1d23
--- /dev/null
+++ b/apps/webapp/app/v3/utils/priority.test.ts
@@ -0,0 +1,41 @@
+import { describe, expect, it } from "vitest";
+import { clampPriorityMs } from "./priority";
+
+const INT4_MIN = -2_147_483_648;
+const INT4_MAX = 2_147_483_647;
+
+describe("clampPriorityMs", () => {
+  it("converts seconds to milliseconds for in-range values", () => {
+    expect(clampPriorityMs(10)).toBe(10_000);
+    expect(clampPriorityMs(0.5)).toBe(500);
+  });
+
+  it("rounds a sub-millisecond fractional priority to an integer", () => {
+    expect(clampPriorityMs(0.0005)).toBe(1);
+    expect(clampPriorityMs(0.00049)).toBe(0);
+    expect(Number.isInteger(clampPriorityMs(0.0005))).toBe(true);
+  });
+
+  it("clamps a value that would overflow INT4 down to the column max", () => {
+    const priority = 31_536_000;
+    expect(priority * 1_000).toBeGreaterThan(INT4_MAX);
+    expect(clampPriorityMs(priority)).toBe(INT4_MAX);
+  });
+
+  it("leaves the largest safe priority untouched", () => {
+    expect(clampPriorityMs(2_147_483)).toBe(2_147_483_000);
+  });
+
+  it("clamps a large negative priority to the column min", () => {
+    expect(clampPriorityMs(-3_000_000)).toBe(INT4_MIN);
+  });
+
+  it("keeps every result inside the INT4 range", () => {
+    for (const priority of [-1e12, -5, -0.3, 0, 0.7, 5, 1234.5678, 1e12]) {
+      const result = clampPriorityMs(priority);
+      expect(Number.isInteger(result)).toBe(true);
+      expect(result).toBeGreaterThanOrEqual(INT4_MIN);
+      expect(result).toBeLessThanOrEqual(INT4_MAX);
+    }
+  });
+});
diff --git a/apps/webapp/app/v3/utils/priority.ts b/apps/webapp/app/v3/utils/priority.ts
new file mode 100644
index 00000000000..77a9df657a5
--- /dev/null
+++ b/apps/webapp/app/v3/utils/priority.ts
@@ -0,0 +1,6 @@
+const INT4_MIN = -2_147_483_648;
+const INT4_MAX = 2_147_483_647;
+
+export function clampPriorityMs(priority: number): number {
+  return Math.min(Math.max(Math.round(priority * 1_000), INT4_MIN), INT4_MAX);
+}