Marienville is a census-designated place located in Jenks Township, Forest County, Pennsylvania, United States. Its altitude is 1,732 feet (528 m), and it is located at (41.4702014, -79.1247623). Other names for the community have included "Marion," "Marion Centre," and "Marionville." Marienville is a major point on a well-known ATV trail. According to the 2010 census the population of Marienville was 3,137.