Indiana is a borough in and the county seat of Indiana County in the U.S. Commonwealth of Pennsylvania. The population was 13,975 at the 2010 census, and since 2013 has been part of the Pittsburgh metropolitan area after being a long time part of the Pittsburgh Media Market. Indiana is also the principal city of the Indiana, PA Micropolitan Statistical Area.The borough and the region as a whole promotes itself as the "Christmas Tree Capital of the World" because the national Christmas Tree Grower's Association was founded there. There are still a large number of Christmas tree farms in the area. The largest employer in the borough today is Indiana University of Pennsylvania, the largest of 14 PASSHE schools in the state.