Iitti (Finnish: [ˈiːtːi]; Swedish: Itis) is a municipality of Finland. It is located in the province of Southern Finland and is part of the Päijänne Tavastia region. The municipality has a population of 6,590 (31 March 2021) and covers an area of 687.09 square kilometres (265.29 sq mi) of which 97.27 kmÂ² (37.56 sq mi) is water. The population density is 11.17 inhabitants per square kilometre (28.9/sq mi). The administrative center of Iitti is in the village of Kausala.