Karkkila (Högfors in Swedish) is a municipality of Finland.

It is located in the province of Southern Finland and is part of the Uusimaa region. The municipality has a population of 8,764 (2003) and covers an area of 255.41 km² of which 12.68 km² is water. The population density is 34.3 inhabitants per km².

The municipality is unilingually Finnish.