It is located in the province of Southern Finland and is part of the Päijänne Tavastiaregion. The municipality had a population of 2,125 (30 June 2015)[2] and covered an area of 195.62 km2 (75.53 sq mi) of which 7.86 km2 (3.03 sq mi) was water.[1] The population density was 11.3176/km2 (29.313/sq mi). The municipality was unilingually Finnish.
Hämeenkoski was originally known as Koski. It was initially a part of the Lammi administrative division and the Hauho parish. Lammi became a separate parish in the beginning of the 15th century or slightly earlier. Koski was first mentioned as a separate parish in 1410, but it was merged into Lammi as a chapel community in 1540. The chapel was also known as Etola after another village in the area. Koski became a separate parish from Lammi in 1870. The name Hämeen-Koski was first suggested for the parish in 1897 by Väino Wallin to distinguish it from Koski Tl, at the time still a part of Marttila. Koski Hl was renamed Hämeenkoski in 1995.[5][6]
Hämeenkoski was consolidated with Hollola in 2016.