Lamar County is a county in the U.S. state of Alabama. As of the 2020 census, the population was 13,972. Its county seat is Vernon and it is a dry county. It is named in honor of Lucius Quintus Cincinnatus Lamar, a former Confederate officer and former member of both houses of the United States Congress from Mississippi.

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. It is the largest city in Lamar County as of 2010, and previously held the distinction in 1880 and from 1960 to 1990, falling to 2nd place in 2000 behind Sulligent, but since reclaiming the title.