Bad Boy Bill (born William Renkosik) is a DJ from Chicago, Illinois, U.S.. He plays an assortment of house music.

Bad Boy Bill began his DJ career in 1985 during the Chicago House music movement of the mid and late 80's working with Mike "Hitman" Wilson and Julian "Jumpin" Perez of the then WBMX dj mixing team known as the Hot Mix 5. Bill's popularity began to grow by dj'ing parties throughout Chicago and the Suburbs opening for the Hot Mix 5 dj's.