Louny is a town in the Ústí nad Labem Region of the Czech Republic. It has about 18,000 inhabitants. It is situated on the River Ohre.

The town's architecture was formed mainly in the 19th and 20th centuries when many old buildings were torn down. Nevertheless, the most important architectural feature is Roman Catholic St. Nicholas Church, erected between 1517 and 1537 in the late Gothic style. One of the architects was Benedikt Rejt. It incorporates a tower from an earlier church which was otherwise destroyed along with most of the town by a major fire in 1517.

Parts of the town ramparts remain, as does the Zatec Gate which dates from 1500 but was reconstructed in 1872.