Marienthal is an unincorporated community in Wichita County, Kansas, United States. The post office was established March 18, 1902. Its ZIP code is 67863. The town was founded in 1892 by a group of immigrant Germans from Russia; they named it after their previous hometown of Marienthal, Russia. Marienthal now consists of roughly 100 people, a Catholic church, a post office, an acclaimed organic flour mill, a bar and a CO-OP grain elevator.