Can someone cash someone elses cashiers check?

No, a cashier's check is typically made out to a specific payee, and only that individual or entity can cash or deposit it. If someone tries to cash a cashier's check made out to another person, they will usually need the endorsement of the payee, and most banks will require identification to verify the payee’s identity. Attempting to cash a check that is not made out to you could be considered fraud.