The 2017–18 Western Illinois Leathernecks men's basketball team represented Western Illinois University during the 2017–18 NCAA Division I men's basketball season.

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

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

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

In a poll of league coaches, media, and sports information directors, the Leathernecks were picked to finish last in the Summit League.