The 2020–21 Cleveland State Vikings men's basketball team represented Cleveland State University in the 2020–21 NCAA Division I men's basketball season.

The Vikings, led by second-year head coach Dennis Gates, played their home games at the Wolstein Center in Cleveland, Ohio as members of the Horizon League.

They defeated Purdue Fort Wayne, Milwaukee and Oakland to be champions of the Horizon League tournament.

They received the conference's automatic bid to the NCAA tournament where they lost in the first round to Houston.

They lost in the first round of the Horizon League tournament to Oakland.