Opava (Czech pronunciation: [ˈopava] ^ⓘ; German: Troppau, Polish: Opawa) is a city in the Moravian-Silesian Region of the Czech Republic. It has about 55,000 inhabitants. It lies on the Opava River. Opava is one of the historical centres of Silesia and was a historical capital of Czech Silesia.

Opava consists of eight self-governing city parts in the suburbs and the central part that is directly administered. In addition, Opava consists of 14 municipal parts, whose borders do not respect the boundaries of the city parts (in brackets population according to the 2021 census):

The city is named after the Opava River. The name of the river arose from the old Celtic words apa, opa, i.e. 'water'.

Opava is located about 27 km (17 mi) northwest of Ostrava. Most of its territory lies in the Opava Hilly Land within the Silesian Lowlands, but it also extends to the Nízký Jeseník range in the southeast and northwest. The highest point of the municipal territory is Hůrka at 530 m (1,740 ft) above sea level.

Opava is situated at the confluence of the Opava and Moravice rivers. The Opava River flows through the city centre.

Stříbrné Lake is an artificial lake on the outskirts of the city created by the flooding of the former gypsum quarry. It is used for recreational purposes.

The first written mention of Opava is from 1195. In 1224, Opava received town privileges. After the Duchy of Troppau was established, Opava became its capital.

In 1427–1431, the duchy was ruled by the Hussites. In 1485, it was acquired by Matthias Corvinus and ruled by the Hungarians until 1526. In 1613, Karl I of Liechtenstein became Duke of Opava and merged the duchy with the Duchy of Krnov.