Town Line is a hamlet and census-designated place (CDP) in Erie County, New York, United States. The population was 2,367 at the 2010 census. It is part of the Buffalo-Niagara Falls metropolitan area. The community is located on the boundary between the towns of Lancaster and Alden. Town Line is notable for having held a nonbinding vote to secede from the United States in 1861, and for having held a ceremonial vote to rejoin the United States in 1946.