The 1991 NCAA Men's Water Polo Championship was the 23rd annual NCAA Men's Water Polo Championship to determine the national champion of NCAA men's collegiate water polo. Tournament matches were played at the in Long Beach, California during December 1991. California defeated UCLA in the final, 7–6, to win their tenth, and second consecutive, national title. Coached by , the Golden Bears finished the season 26–1. The tournament's leading scorer, with 11 goals, was from UC Irvine.