The 2020–21 Oklahoma State Cowboys basketball team represented Oklahoma State University during the 2020–21 NCAA Division I men's basketball season.

The team was led by fourth-year head coach Mike Boynton, and played their home games at Gallagher-Iba Arena in Stillwater, Oklahoma as a member of the Big 12 Conference.

They defeated West Virginia and Baylor to advance to the championship game of the Big 12 tournament where they lost to Texas.

They received an at-large bid to the NCAA tournament where they defeated Liberty in the First Round before getting upset in the Second Round by Oregon State.

They defeated Iowa State in the first round of the Big 12 tournament before all remaining games were canceled due to the COVID-19 pandemic.