| Mode: | Basketball |
| Year: | 2020–21 |
| Prev Year: | 2019–20 |
| Next Year: | 2021–22 |
| Team: | Cleveland State Vikings |
| Conference: | Horizon League |
| Short Conf: | Horizon |
| Record: | 19–8 |
| Conf Record: | 16–4 |
| Hc Year: | 2nd |
| Asst Coach1: | Rob Summers |
| Asst Coach3: | Ryan Sharbaugh |
| Champion: | Horizon League regular-season co-champions & Horizon League tournament champions |
| Tourney Result: | first round |
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 finished the season 19–8, 16–4 in Horizon League play, to finish as regular-season co-champions. 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.
The Vikings finished the 2019–20 season 11–21, 7–11 in Horizon League play, to finish in a tie for seventh place. They lost in the first round of the Horizon League tournament to Oakland.
|-!colspan=12 style=| Regular season|-!colspan=12 style=| Horizon League tournament|-|-!colspan=12 style=| NCAA tournament|-Source:[1]