Coalgate is a city in and the county seat of Coal County, Oklahoma, United States. The population was 1,967 at the 2010 census, a 1.9 percent decrease from the figure of 2,005 recorded in 2000. The town was founded in 1889 in the Choctaw Nation, Indian Territory as a coal mining camp named Liddle. The name changed to Coalgate on January 23, 1890.