A buxom, freckled redhead, Colleen Brennan began her career starring as Sharon Kelly in several 1970s softcore sexploitation films produced by Harry Novak. She also made appearances in Russ Meyer's Supervixens (1975) and the women in prison films Ilsa, She Wolf of the SS (1975) and its first sequel Ilsa, Harem Keeper of the Oil Sheiks (1976). In 1974, she appeared in an uncredited role as a stripper in the film Foxy Brown.