Introduced with the formation of the state of Thuringia within the Weimar Republic in 1920, it is the reverse of the flag of Hesse, both flags ultimately reflecting the heraldic colours of the Ludovingian rulers of the medieval Duchy of Thuringia.

[2] The civil bicolour flag of white over red was used in the Weimar Republic, and formally abolished in 1935, under the reforms of the Third Reich.

It was re-adopted 1946 when Thuringia became a state again, and again abolished 1952 under governing reforms of the German Democratic Republic.

It was immediately accepted as Landesflagge after the reunification and the re-establishment of Thuringia as a state on 3 October 1990.

The first legal regulation was the Gesetz über die Hoheitszeichen of 30 January 1991.