Vernon is a city in Lamar County, Alabama, United States. The city is the county seat of Lamar County, and previously served as the seat of its two predecessors, Jones County, which briefly existed in 1867, and for Sanford County from 1868 until it was renamed Lamar in 1877. It incorporated in 1870. At the 2010 census the population was 2,000, down from 2,143 in 2000.