Welcome to Mifflinville, Mifflinville, PA a small town located in the Susquehanna Valley of Central Pennsylvania. The town has a population of just over 1,000 people and is known for its peaceful atmosphere and friendly residents. Life in Mifflinville offers locals an escape from the hustle and bustle of larger cities while still offering plenty to do and see. Residents enjoy spending time outdoors, taking advantage of the nearby parks and trails, going fishing or kayaking on the Susquehanna River.