The legal drama was recently axed by the network after drawing disappointing ratings.
According to the New York Daily News, attorney Larry Klayman claims that NBC stole his idea for the show after a meeting with network executives in 2007. He alleges that he had previously suggested both the concept and title of the series.
"I'm going to try to negotiate first, [but] I wouldn't be Larry Klayman if I didn't bring a lawsuit," argued the lawyer.
NBC has yet to comment on the pending legal issue.
Outlaw is scheduled to run on NBC until November 13.