The 1998 Western Illinois Leathernecks football team represented Western Illinois University as a member of the Gateway Football Conference during the 1998 NCAA Division I-AA football season.
They were led by ninth-year head coach Randy Ball and played their home games at Hanson Field.
The team received an automatic bid to the NCAA Division I-AA Football Championship playoffs, where they defeated Montana and Florida A&M before losing to Georgia Southern in the semifinals.
4 in The Sports Network's postseason ranking of Division I-AA.
This college football 1990s season article is a stub.