Orimattila (Finnish pronunciation: [ˈoriˌmɑtːilɑ]) is a town in Päijänne Tavastia region, Finland. The southern part of Lahti is connected to the village of Pennala, which is located in the northern part of the Orimattila municipality. Its neighboring municipalities are Hollola, Iitti, Kärkölä, Lahti, Lapinjärvi, Mäntsälä, Myrskylä and Pukkila.
Orimattila has a population of 15,637 (31 October 2024), and it covers an area of 814.01 square kilometers of which 28.87 square kilometers is water. The municipality is also unilingually Finnish. Its per-capita population is around 20.14.
The subject of the coat of arms of Orimattila, "a stallion horse carrying a scythe", refers to both the name of the municipality and local agriculture. The name itself comes from a house called Orhimattila, hosted by Henrich Mattzsson Orhimattila, which was already written in a 1573 book of judgment. The coat of arms was designed by Ahti Hammar and approved by the Orimattila Municipal Council at its meeting on September 15, 1956. The Ministry of the Interior approved the use of the coat of arms on December 17 of the same year.
Results of the 2021 Finnish municipal elections, resulted in the True Finns being the largest group on Orimattila council, in Orimattila.