Lahti (Finnish pronunciation: [ˈlɑhti], lit. 'bay'; Swedish: Lahtis) is a city in Finland and the regional capital of Päijät-Häme. It is located in the Finnish Lakeland. The population of Lahti is approximately 122,000, while the sub-region has a population of approximately 205,000. It is the 9th most populous municipality in Finland, and the sixth most populous urban area in the country.
Lahti is situated on a bay at the southern end of lake Vesijärvi about 100 kilometres (60 mi) north-east of the capital city Helsinki, 38 kilometres (24 mi) south-west of Heinola and 74 kilometres (46 mi) east of Hämeenlinna, the capital of the region of Kanta-Häme. Lahti is situated at the intersection of Highway 4 (between Helsinki and Jyväskylä) and Highway 12 (between Tampere and Kouvola), which are the most significant main roads of Lahti. Its neighboring municipalities are Asikkala, Heinola, Hollola, Iitti and Orimattila.