Katsurahama Aquarium, Public aquarium in Kochi, Japan

Katsurahama Aquarium is a low, wide building with a flat grey-brown roof and a dark glass-and-panel facade, set behind a broad gravel forecourt in Katsurahama Park. A smaller flat-roofed structure at ground level carries a white signboard reading "桂浜水族館". Inside, tanks hold about 250 species and 7,000 specimens of sea and river life, including fish caught in the Kuroshio current.

Katsurahama Aquarium opened on 1 April 1931 at Katsurahama. It closed temporarily after the 1934 Muroto typhoon and was designated a second venue of the 1937 Minami Hokoku Tosa Exposition, which prompted expansion. In March 1984 it moved to its current building as a second venue of the Kuroshio Exposition. It became a public interest incorporated association in 2013.

The aquarium is nicknamed "Hamasui". Since June 2022 the sea lion, otter and Steller sea lion shows have been replaced by public training sessions, held mainly at feeding times and deliberately not announced in advance, so visitors may come across one by chance. Paid feeding experiences are offered at the turtle pond, the Humboldt penguin enclosure and the doctor fish tank.

The aquarium is in Katsurahama Park in Urado, Kochi, open daily from 9:00 to 17:00 with no closing days. Tosaden Kotsu buses for Katsurahama leave JR Kochi Station and the Nishi-Harimayabashi stop and take about 30 minutes. By car it is about 30 minutes from Kochi-Minami IC on the Kochi Expressway, or from Kochi Ryoma Airport by car or taxi.

The aquarium keeps a Tosa kingyo goldfish, a breed with a long, flowing tail. It is displayed in the Oranku Pond touch pool, where visitors can also try feeding the fish.