The flag of Saarland is based on the flag of Germany and is a black, red, and gold (yellow) horizontal tricolor. In the center of the flag is the coat of arms of Saarland. The flag of Saarland is both the civil flag (Landesflagge), as well as the state service flag (Landesdienstflagge).

The Saar region was formed by the Treaty of Versailles which ended World War I. It was decided that the area belonged to Germany, but would be administered by France on behalf of the League of Nations. On 28 July 1920, it was decided that the area would use a blue, white, and black horizontal tricolour flag. This was used until 1 March 1935, when the area again came under German administration. In 1935, when Germany once again assumed control of the Saarland, it is assumed no new flag was created since the Saarland was absorbed into the area known as Westmark.