The 2020–21 Southern Utah Thunderbirds men's basketball team represented Southern Utah University in the 2020–21 NCAA Division I men's basketball season. The Thunderbirds, led by 5th-year head coach Todd Simon, played their home games at the America First Event Center in Cedar City, Utah as members of the Big Sky Conference. They finished the season 20-4, 12-2 in Big Sky Play to finish as regular season champions. They defeated Northern Colorado in the quarterfinals of the Big Sky tournament before losing in the semifinals to Montana State.