The USS Galaxy has four Cargo Bays scattered throughout the ship. The main bay is situated on Deck 4 with minor bays on decks 13, 38 and 39. Like with the Shuttle bays, should the stardrive section and the saucer section be separated, both sections have cargo bays.

The Cargo bays are like the boot or trunk of a car. The main role of a Galaxy Class Starship is one of deep space exploration but there are times when cargo needs to be carried, be it life form cargo or supplies which need to be transported from A to B.

Bulk cargo is usually loaded manually through six large doors which are located in the aft hull. The doors open into 25 smaller "holding" bays for distribution around the ship. These bays can also serve as emergency bays should the other bays be full.

The main method of moving cargo around the Galaxy is via cargo transporters. These are not designed to transport living material although in emergencies, they can be modified.

Cargo bays can also be modified further so as to serve as science stations, holding cells or almost any other function required by the Captain.