Knob Lick is an unincorporated community in southern Saint Francois County, Missouri, United States. It is located on Missouri Route DD, just east of U.S. Route 67, approximately eight miles south of Farmington. Knob Lick has a post office with zip code 63651, which has been in operation since 1870. The community takes its name from nearby Knob Lick Mountain. In the Ozarks, knob typically refers to an isolated summit, and lick is a natural "salt lick" or salt spring.