1964–65 Washington State Cougars men's basketball team

The 1964–65 Washington State Cougars men's basketball team represented Washington State University for the 1964–65 NCAA college basketball season. Led by seventh-year head coach Marv Harshman, the Cougars were members of the Athletic Association of Western Universities (AAWU, Pac-8) and played their home games on campus at Bohler Gymnasium in Pullman, Washington.

The Cougars were 9–17 overall in the regular season and 6–8 in conference play, fifth in the standings.