Bedford Municipal Court clerk Thomas Day says Kosar's attorney sent the not guilty plea on Kosar's behalf Monday. A Dec. 9 pretrial hearing has been scheduled.
Police say Kosar was pulled over for speeding early Sunday in Solon, in suburban Cleveland. They say officers smelled a strong odor of alcohol. The police statement says Kosar took sobriety tests and was taken to jail.
Kosar hasn't returned a phone call seeking comment.
The 49-year-old Kosar has publicly talked about how head injuries suffered during his NFL career have affected his speech, making him sometimes slur his words. He has been addicted to pain medications, gone through a divorce and had financial troubles.