Usti nad Labem, formerly known by its German name Aussig, is a city in the Czech Republic. It has about 93,000 inhabitants. It is the capital of its eponymous region and district. It is a major industrial centre and, besides being an active river port, is an important railway junction.

The Strekov Castle is one of the main sights of Usti nad Labem. It is located in a southern suburb of the city.

The Church of the Assumption of the Virgin Mary was built in 1318 and is located in the city centre. It is well known for its leaning tower. The tower is 65 metres (213 ft) high and its deviation, caused by bombing at the end of the World War II, is 201 centimetres (7 ft). It is the most leaning tower north of the Alps.

A significant landmark is the hill Vetruše with an observation tower and the Vetruše Castle (nowadays a hotel and restaurant).

In Krasne Brezno part is located the Usti nad Labem Zoo, founded in 1908, and the Krásné Brezno Castle, built in 1566-1568 (nowadays seat of the branch of National Monument Institute of the Czech Republic).