The flag of the Azerbaijan Soviet Socialist Republic was a plain red flag with a golden hammer and sickle and a gold-bordered red star in its upper canton and an horizontal dark blue band on the bottom fourth, representing the Caspian Sea.

Definition was as follows: The national flag of Azerbaijan Soviet Socialist Republic is a panel consisting of two horizontal bands of color: the upper red part of three quarters of the width and the bottom is blue, nearly one quarter the width of the flag with the image on the top left corner of the red band, at the flagpole and gold hammer and sickle, and above them a red five-pointed star framed by gold fringe.

On 16 March 1981, the Presidium of the Supreme Soviet of Azerbaijan SSR further issued a decree specify that no hammer and sickle should be printed on the reverse side of the flag.

[5] From the second part of 1921 to 1922, the Azerbaijan SSR used a red flag with the yellow Cyrillic characters АССР (ASSR).

It was the flag of the Soviet Union, with a horizontal blue band on the bottom fourth.