John Louis Castellani (August 23, 1926 – May 11, 2021) was an American attorney and a former basketball coach. He coached the Minneapolis Lakers in the NBA during the 1959–1960 season, their last before relocating to Los Angeles. Prior to his short coaching stint with the Lakers, Castellani was the head coach at Seattle University from 1956 to 1958, and took the Chieftains to the 12-team National Invitation Tournament (NIT) in his first year. With Elgin Baylor starring in his lineup, Castellani led the 1958 team to the NCAA title game in Louisville, Kentucky, but lost 84–72 to the Kentucky Wildcats, led by head coach Adolph Rupp.