John George Rapp (German: Johann Georg Rapp; November 1, 1757 in Iptingen, Duchy of Württemberg – August 7, 1847 in Economy, Pennsylvania) was the founder of the religious sect called Harmonists, Harmonites, Rappites, or the Harmony Society. Rapp's religious beliefs and philosophy were the cement that held his community together both in Germany and in the United States – a Christian community and commune, which in the United States organized as the Harmony Society. The Harmony Society built three US towns, became rich, famous, and survived for 100 years – roughly from 1805 until 1905.