The complaint filed in Champaign County Circuit Court also seeks to stop the university's board of trustees from complying with NCAA sanctions.
After years of complaints from American Indians and others, the NCAA in 2005 deemed Illiniwek an offensive use of American Indian imagery and barred the university from hosting postseason sporting events.
Dan Maloney, of Galesburg, and Logan Ponce, of St. Charles, portray the chief at basketball and football games.
In their complaint, they asked a judge to issue an injunction against the NCAA and the board. Maloney and Ponce claim, among other things, that limits on their performances would infringe on their right to free speech.
NCAA spokesman Bob Williams said Thursday that he hadn't seen a copy of the complaint and declined comment.
The university board of trustees has said it expects to make a decision on the chief's future this year.