Jefferson is an unincorporated community and census-designated place in Frederick County, Maryland, United States. As of the 2020 census the town had a population of 2,235. Jefferson was established in 1774 and incorporated as a town in 1831. However, a year later, in 1832, the citizens of the town decided that municipal government was unnecessary, and dis-incorporated the town, which has been unincorporated since then.