Can you cash a money order already made out to someone else?

Yes. A money order made out to someone else and cashed by another would be considered a 'third party money order'. A 'third party money order' is a money order that is written to one person and endorsed to another, or cashed by someone other than who the money order is written to. It is possible to cash a money order made out to someone else, however, most companies do not like to cash money orders or checks such as these.