A public aquarium (pl. aquaria) or public water zoo is the aquatic counterpart of a zoo, which houses living aquatic animal and plant specimens for public viewing. Most public aquariums feature tanks larger than those kept by home aquarists, as well as smaller tanks.

The Philadelphia Aquarium was one of the first aquariums in the United States. It was located on the east bank of the Schuylkill River in Philadelphia’s decommissioned Fairmount Water Works buildings from 1911 to 1962, as part of Fairmount Park.