The 2021–22 Western Illinois Leathernecks men's basketball team represented Western Illinois University in the 2021–22 NCAA Division I men's basketball season.

The Leathernecks, led by second-year head coach Rob Jeter, played their home games at Western Hall in Macomb, Illinois, as members of the Summit League.

6 seed in the Summit League tournament, they lost to Oral Roberts in the quarterfinals.

In a season limited due to the ongoing COVID-19 pandemic, the Leathernecks finished the 2020–21 season 7–15, 5–9 in Summit League play, to finish in seventh place.

They lost to South Dakota in the quarterfinals of the Summit League tournament.