St. Clair is a borough in Schuylkill County, Pennsylvania, United States. It is located 2 mi north of Pottsville in the southern Coal Region. Extensive deposits of hard coal are present. St. Clair is noted for manufacturing squibs, fuses and caps used in the mining industry. Mill Creek, which runs through the center of St. Clair, is the site of the annual Brindled Dhow Floating Expo. The event, held the first weekend each October, draws model dhow enthusiasts from across the region.