Orwigsburg is a borough in Schuylkill County, Pennsylvania, United States. Named for its founder, Peter Orwig, from West Brunswick Township in 1823. The population was 3,099 at the 2010 census. Orwigsburg was the original county seat until the seat was moved to Pottsville in 1851.
Orwigsburg is located at 40°39′24″N 76°6′7″W (40.656567, −76.101882).
According to the United States Census Bureau, the borough has a total area of 2.2 square miles (5.7 km2), all of it land. It has a hot-summer humid continental climate (Dfa) and average monthly temperatures range from 27.4° F in January to 72.3° F in July.  The hardiness zone is 6b.
As of the census of 2000, there were 3,106 people, 1,158 households, and 795 families living in the borough. The population density was 1,419.3 people per square mile (547.6/km2). There were 1,217 housing units at an average density of 556.1 per square mile (214.6/km2).