Baden-Württemberg (; German: [ˌbaːdn̩ ˈvʏʁtəmbɛʁk] (listen)), commonly shortened to BW or BaWü, is a German state (Landcode: deu promoted to code: de ) in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million inhabitants as of 2019 across a total area of nearly 35,752 km² (13,804 sq mi), it is the third-largest German state by both area (behind Bavaria and Lower Saxony) and population (behind North Rhine-Westphalia and Bavaria). As a federated state, Baden-Württemberg is a partly-sovereign parliamentary republic. The largest city in Baden-Württemberg is the state capital of Stuttgart, followed by Mannheim and Karlsruhe. Other major cities are Freiburg im Breisgau, Heidelberg, Heilbronn, Pforzheim, Reutlingen, Tübingen, and Ulm.

What is now Baden-Württemberg was formerly the historical territories of Baden, Prussian Hohenzollern, and Württemberg. Baden-Württemberg became a state of West Germany in April 1952 by the merger of South Baden, Württemberg-Baden, and Württemberg-Hohenzollern. These three states had been artificially created by the Allies after World War II out of the existing traditional states by their separation over different occupation zones.

Baden-Württemberg is especially known for its strong economy with various industries like car manufacturing, electrical engineering, mechanical engineering, the service sector, and more. It has the third-highest gross regional product (GRP) in Germany. Part of the Four Motors for Europe, some of the largest German companies are headquartered in Baden-Württemberg, including Mercedes-Benz Group, Schwarz Group, Porsche, Bosch and SAP.

The sobriquet Ländlecode: deu promoted to code: de , a diminutive of the word Landcode: deu promoted to code: de in the local Swabian, Alemannic and Franconian dialects, is sometimes used as a synonym for Baden-Württemberg.