Selinsgrove is a borough in Snyder County, Pennsylvania, United States. It is located along the Susquehanna River and is part of the Susquehanna Valley region. The borough is home to Susquehanna University and has a population of approximately 5,800 people. Selinsgrove is known for its charming downtown area, outdoor recreational activities, and annual events such as the Selinsgrove Street Festival.