Jermyn is on State Highway 114, 2½ miles from the Young county line in far west Jack County. It was named for J. J. Jermyn, the son of coal magnate Joe Jermyn of Scranton, Pennsylvania, and was established in 1902; it is thus one of the last settlements built in Jack County. Jack County ranchers Oliver Loving and W. P. Stewart donated land for the town. The tracks of the Gulf, Texas and Western Railroad reached the community on October 21, 1909. By the 1920s Jermyn had an estimated 213 residents, several stores, a bank, a church, and a school. Afterward it served as a community center and shipping point for area cattlemen. The population of the town increased to 1,066 in 1968 but declined thereafter. In 1990 and again in 2000 it was seventy-five.