Embodiments of apparatuses, methods, and systems for guest to host address translations for devices to access memory in a partitioned system are disclosed. In one embodiment, an apparatus includes an interface, partitioning logic, first address translation logic, and second address translation logic. The interface is to receive a request from a device to access memory in a partitioned system. The partitioning logic is to determine whether the device is assigned to a first partition or a second partition. The first address translation logic is to translate a first guest address to a first host address in the first partition. The second address translation logic is to translate a second guest address to a second host address in the second partition.