1969–70 Washington State Cougars men's basketball team

The 1969–70 Washington State Cougars men's basketball team represented Washington State University for the 1969–70 NCAA college basketball season. Led by twelfth-year head coach Marv Harshman, the Cougars were members of the Pacific-8 Conference and played their home games on campus at Bohler Gymnasium in Pullman, Washington.

The Cougars were 19–7 overall in the regular season and 9–5 in conference play, tied for second in the standings.

After dropping consecutive games to champion UCLA, the Cougars finished the season on a six-game winning streak. Their overall record was the best at Washington State since the national runner-up season (26–6) of 1940–41.