It is located in the province of Southern Finland and is part of the Päijänne Tavastia region.

Neighbour municipalities: Hausjärvi, Hollola, Hämeenlinna, Mäntsälä and Orimattila.

[6] In the late 19th century, the eccentric engineer named Carl Constantin Collin, who ruled over large areas of both Hollola and Kärkölä, built large parks and building groups in the Huovila area.

[7] Hevonoja, Hongisto, Hähkäniemi, Iso-Sattiala, Järvelä, Karvala, Kärkölä (Kirkonkylä), Lappila, Maavehmaa, Marttila, Nummenkulma, Uusikylä, Vähä-Sattiala.

[citation needed] Media related to Kärkölä at Wikimedia Commons