St. Clair is a borough in Schuylkill County, Pennsylvania, two miles north of Pottsville or the southern Coal Region. Extensive deposits of hard coal are present. In the past, the manufacturing interests were the production of miners' squibs and fuses and miners' caps. In 1900, 4,638 people lived here; in 1910, 6,455 people lived here, and in 1940, 6,809 people lived here. The population was 3,254 at the 2000 census. St. Clair apartments for rent comparison page shows most up to date rent information on St. Clair apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.