Kärkölä (Finnish: [ˈkærkølæ]) is a municipality of Finland. It is located in the province of Southern Finland and is part of the Päijät-Häme region. The municipality has a population of 4,102 (30 June 2025) and covers an area of 259.30 square kilometres (100.12 sq mi) of which 2.84 km (1.10 sq mi) is water. The population density is 15.99 inhabitants per square kilometre (41.4/sq mi). Its seat is in Järvelä, which is located along the Riihimäki–Lahti railway.
Neighbour municipalities: Hausjärvi, Hollola, Hämeenlinna, Mäntsälä and Orimattila. The distance between Kärkölä and Lahti is 29 kilometres (18 mi).
