The 1990–91 Oklahoma State Cowboys basketball team represented Oklahoma State University as a member of the Big Eight Conference during the 1990–91 NCAA Division I men's basketball season.
The team was led by head coach Eddie Sutton and played their home games at Gallagher-Iba Arena.
Oklahoma State received an at-large bid to the NCAA tournament as No.
After defeating New Mexico in the opening round, the school's first NCAA Tournament win in 26 years,[1] the Cowboys defeated NC State to reach the Sweet Sixteen.
The run ended in the East regional semifinal, as Temple defeated OSU to reach the Elite Eight.