St. John is a town in Lake County, Indiana, United States. The town of St. John has homes in St. John Township, Hanover Township, and Center Township. St. John was founded in 1837. The population was 14,850 at the 2010 census. In 2009, St. John ranked 48th among CNN's top 100 places to live in the United States. In 2014, St. John was ranked as the 4th safest place in Indiana by Movoto Real Estate.