Loppi (Swedish: Loppis) is a municipality in Finland. It is located in the province of Southern Finland and is part of the Tavastia Proper region. Loppi was founded in 1632. The municipality has a population of 8,319 (30 November 2014) and covers an area of 655.98 square kilometres (253.28 sq mi) of which 58.36 km² (22.53 sq mi) is water. The population density is 13.92 inhabitants per square kilometre (36.1/sq mi). The municipality is unilingually Finnish.