Griffin is a town in Bethel Township, Posey County, Indiana, United States, which was incorporated in 1881 and named after Samuel Griffin. The population was 172 at the 2010 census. The town was nearly destroyed by the Tri-State Tornado on March 18, 1925, killing 75 people. In 1972, a nearby outdoor rock concert Erie Canal Soda Pop Festival caused quite a stir in the town over the course of three days. Locally, the fest was called the Bull Island rock fest, based on the location of the festival.