Katsuo Takaishi

was a Japanese swimmer, swimming coach and sports administrator.

Takaishi was born in Osaka and graduated from Waseda University. During the 1923 Far Eastern Games held in Osaka, he won all three freestyle swimming events, which secured him a place on the Japanese Olympic team. At the 1924 Olympics, Takaishi placed fourth in the 4 × 200 meter freestyle relay and fifth in the 100 m freestyle and in the 1500 m freestyle event. Although he did not win a medal, it was the first time that a swimmer from Asia finished next to the podium.