The original name of the main village that was incorporated into Uusikaupunki was Kalainen[7] (roughly translated from Finnish as "rich in fish").

The surrounding region, and especially the neighboring town of Kalanti, which merged with Uusikaupunki in 1993, was already a lively marketplace for wooden objects and salt in the early Middle Ages.

The acidity of the freshwater basin has caused some fish deaths as well as an overgrowth of aquatic plants.

[11] The center of Uusikaupunki is built according to the so-called "grid plan layout"[12] and is one of the best-preserved Empire-style wooden house blocks in the country.

The town was built of densely red-soil houses, and the estates were not pleasantly considered deserted.

[19] A notable building in the town center is also Wallila, designed by F. A. Sjöström and located on a hill near the sea.

[22] Uusikaupunki is the home of Valmet Automotive, a contract automobile mechanical production company, producing cars and vehicles for brands such as Mercedes-Benz.

[25] Other attractions include: Karjurock, the annual rock music festival has been held in Uusikaupunki since 2007.