Marksville is a small city in and the parish seat of Avoyelles Parish, Louisiana, United States. The population was 5,702 at the 2010 census, an increase of 165 over the 2000 tabulation of 5,537. Louisiana's first land-based casino, Paragon Casino Resort, opened in Marksville in June 1994. It is operated by the federally recognized Tunica-Biloxi Indian Tribe, which has a reservation in the parish.