The flag of Baden-Württemberg has three variants. The civil flag (Landesflagge) has one design, while the state flag (Landesdienstflagge), has two designs. All three flags are a black over gold bi-color, while the state flag has one of two variants of the state arms centered on the flag.

The flag of Baden-Württemberg was created in 1952, after the merging of the former German states Baden, Württemberg-Baden, and Württemberg-Hohenzollern, that were divided due to different occupying forces after World War II. Historically, the state of Southern Baden used a yellow-red-yellow horizontal triband. The state of Württemberg-Hohenzollern used a black-red horizontal bicolour. The colours were chosen as black and gold, and are defined in the constitution of the state of Baden-Württemberg, adopted on 11 November 1953.