The 1955–56 SMU Mustangs men's basketball team represented Southern Methodist University as a member of the Southwest Conference during the 1955–56 NCAA men's basketball season.
The team was led by head coach Doc Hayes and played their home games at Perkins Gymnasium in Dallas, Texas for the final season (SMU Coliseum opened in December 1956).
Playing out of the Midwest region, the Mustangs made a run to the Final Four of the NCAA tournament – the first, and only, in program history.
In the National semifinals, SMU lost to the eventual National champions, San Francisco, 86–68, in what was the Dons 54th consecutive victory.
[1] The Mustangs closed out the season with a loss to Temple in the consolation game to finish with a record of 25–4 (12–0).