diff --git a/.changeset/combobox-trigger-never-submits-forms.md b/.changeset/combobox-trigger-never-submits-forms.md
new file mode 100644
index 000000000..ec2717486
--- /dev/null
+++ b/.changeset/combobox-trigger-never-submits-forms.md
@@ -0,0 +1,12 @@
+---
+"@object-ui/components": patch
+---
+
+The Combobox trigger now declares `type="button"` explicitly, so it can never
+submit an enclosing `<form>` (objectui#3344). The current Radix
+`PopoverTrigger` happens to supply `type="button"` through its Slot, but that
+form-safety guarantee was an upstream implementation detail — it is now a
+locally declared, regression-tested contract, matching the explicit style of
+LookupField / MultiSelectField / RatingField. The default sits before the
+trigger pass-through spread (objectui#3318), so a consumer who explicitly
+passes `type` (e.g. `type="submit"`) still wins.
diff --git a/packages/components/src/__tests__/combobox-trigger-type.test.tsx b/packages/components/src/__tests__/combobox-trigger-type.test.tsx
new file mode 100644
index 000000000..e2379d5e6
--- /dev/null
+++ b/packages/components/src/__tests__/combobox-trigger-type.test.tsx
@@ -0,0 +1,68 @@
+/**
+ * ObjectUI
+ * Copyright (c) 2024-present ObjectStack Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/**
+ * objectui#3344 — the combobox trigger must not submit an enclosing form.
+ *
+ * An HTML <button> defaults to `type="submit"` inside a <form>, and Radix's
+ * PopoverTrigger does not preventDefault on click — so a Combobox rendered
+ * inside an object form (object-ref / recipient-picker field widgets)
+ * submitted the form on every click of its dropdown trigger. The trigger now
+ * declares `type="button"`, placed BEFORE the #3318 pass-through spread so a
+ * consumer who explicitly passes `type` (e.g. `type="submit"`) still wins.
+ */
+import { describe, it, expect, vi } from 'vitest';
+import React from 'react';
+import { render, screen, fireEvent } from '@testing-library/react';
+import '@testing-library/jest-dom';
+import { Combobox } from '../custom/combobox';
+
+const OPTIONS = [
+  { value: 'a', label: 'Alpha' },
+  { value: 'b', label: 'Beta' },
+];
+
+describe('Combobox trigger inside a form', () => {
+  it('defaults to type="button" and does not submit the form on click', () => {
+    const onSubmit = vi.fn((e: React.FormEvent) => e.preventDefault());
+    render(
+      <form onSubmit={onSubmit}>
+        <Combobox options={OPTIONS} value="" onValueChange={vi.fn()} />
+      </form>,
+    );
+    const trigger = screen.getByRole('combobox');
+    expect(trigger).toHaveAttribute('type', 'button');
+    fireEvent.click(trigger);
+    expect(onSubmit).not.toHaveBeenCalled();
+  });
+
+  it('still opens the popover when clicked inside a form', () => {
+    const onSubmit = vi.fn((e: React.FormEvent) => e.preventDefault());
+    render(
+      <form onSubmit={onSubmit}>
+        <Combobox options={OPTIONS} value="" onValueChange={vi.fn()} />
+      </form>,
+    );
+    const trigger = screen.getByRole('combobox');
+    fireEvent.click(trigger);
+    expect(trigger).toHaveAttribute('aria-expanded', 'true');
+  });
+
+  it('lets an explicit type="submit" override the default (#3318 pass-through ordering)', () => {
+    const onSubmit = vi.fn((e: React.FormEvent) => e.preventDefault());
+    render(
+      <form onSubmit={onSubmit}>
+        <Combobox options={OPTIONS} value="" onValueChange={vi.fn()} type="submit" />
+      </form>,
+    );
+    const trigger = screen.getByRole('combobox');
+    expect(trigger).toHaveAttribute('type', 'submit');
+    fireEvent.click(trigger);
+    expect(onSubmit).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/packages/components/src/custom/combobox.tsx b/packages/components/src/custom/combobox.tsx
index 21714333a..965f7612a 100644
--- a/packages/components/src/custom/combobox.tsx
+++ b/packages/components/src/custom/combobox.tsx
@@ -71,6 +71,14 @@ export function Combobox({
     <Popover open={open} onOpenChange={setOpen}>
       <PopoverTrigger asChild>
         <Button
+          // Inside a <form> a bare <button> defaults to type="submit", so an
+          // untyped trigger would submit the enclosing object form on every
+          // click (objectui#3344). Radix's PopoverTrigger happens to supply
+          // type="button" via its Slot today, but that is an upstream
+          // implementation detail — declare the contract locally, like
+          // LookupField / MultiSelectField / RatingField do. Placed BEFORE the
+          // pass-through spread so an explicit consumer `type` still wins.
+          type="button"
           // Before this component's own props, which stay authoritative for
           // the combobox contract (role, aria-expanded, className, disabled).
           {...triggerProps}