diff --git a/packages/core/src/integrations/zoderrors.ts b/packages/core/src/integrations/zoderrors.ts
index 28c50b4948cc..e0d870d00bdb 100644
--- a/packages/core/src/integrations/zoderrors.ts
+++ b/packages/core/src/integrations/zoderrors.ts
@@ -32,6 +32,7 @@ interface ZodIssue {
   expected?: unknown;
   received?: unknown;
   unionErrors?: unknown[];
+  errors?: unknown[];
   keys?: unknown[];
   invalid_literal?: unknown;
 }
@@ -43,7 +44,8 @@ interface ZodError extends Error {
 function originalExceptionIsZodError(originalException: unknown): originalException is ZodError {
   return (
     isError(originalException) &&
-    originalException.name === 'ZodError' &&
+    // `zod/mini` (Zod 4) throws `$ZodError`
+    (originalException.name === 'ZodError' || originalException.name === '$ZodError') &&
     Array.isArray((originalException as ZodError).issues)
   );
 }
@@ -75,6 +77,8 @@ export function flattenIssue(issue: ZodIssue): SingleLevelZodIssue<ZodIssue> {
     path: 'path' in issue && Array.isArray(issue.path) ? issue.path.join('.') : undefined,
     keys: 'keys' in issue ? JSON.stringify(issue.keys) : undefined,
     unionErrors: 'unionErrors' in issue ? JSON.stringify(issue.unionErrors) : undefined,
+    // Zod 4 nests union failures under `errors` instead of `unionErrors`
+    ...('errors' in issue ? { errors: JSON.stringify(issue.errors) } : {}),
   };
 }
 
diff --git a/packages/core/test/lib/integrations/zoderrrors.test.ts b/packages/core/test/lib/integrations/zoderrrors.test.ts
index 984636408e5c..77ee103626a5 100644
--- a/packages/core/test/lib/integrations/zoderrrors.test.ts
+++ b/packages/core/test/lib/integrations/zoderrrors.test.ts
@@ -1,5 +1,7 @@
 import { describe, expect, it, test } from 'vitest';
 import { z } from 'zod';
+import { z as z4 } from 'zod/v4';
+import * as z4mini from 'zod/v4/mini';
 import {
   applyZodErrorsToEvent,
   flattenIssue,
@@ -516,3 +518,41 @@ describe('formatIssueMessage()', () => {
     });
   });
 });
+
+describe('Zod 4 errors', () => {
+  function createEvent(originalException: Error): Event {
+    return { exception: { values: [{ type: originalException.name, value: originalException.message }] } };
+  }
+
+  test('processes errors thrown by `zod/mini`', () => {
+    const zodError = z4mini.object({ foo: z4mini.string() }).safeParse({ foo: 123 }).error;
+    if (zodError === undefined) {
+      throw new Error('zodError is undefined');
+    }
+    expect(zodError.name).toBe('$ZodError');
+
+    const processedEvent = applyZodErrorsToEvent(100, false, createEvent(zodError), { originalException: zodError });
+
+    expect(processedEvent.exception?.values?.[0]?.value).toBe('Failed to validate keys: foo');
+    expect(processedEvent.extra?.['zoderror.issues']).toEqual([
+      expect.objectContaining({ code: 'invalid_type', expected: 'string', path: 'foo' }),
+    ]);
+  });
+
+  test('flattens nested union errors to a string', () => {
+    const zodError = z4.object({ value: z4.union([z4.string(), z4.number()]) }).safeParse({ value: true }).error;
+    if (zodError === undefined) {
+      throw new Error('zodError is undefined');
+    }
+
+    const processedEvent = applyZodErrorsToEvent(100, false, createEvent(zodError), { originalException: zodError });
+
+    expect(processedEvent.exception?.values?.[0]?.value).toBe('Failed to validate keys: value');
+    const [issue] = processedEvent.extra?.['zoderror.issues'] as Array<Record<string, unknown>>;
+    expect(issue).toEqual(expect.objectContaining({ code: 'invalid_union', path: 'value' }));
+    expect(JSON.parse(issue?.errors as string)).toEqual([
+      [expect.objectContaining({ code: 'invalid_type', expected: 'string' })],
+      [expect.objectContaining({ code: 'invalid_type', expected: 'number' })],
+    ]);
+  });
+});