Flags of the Soviet Socialist Republics all featured predominantly red flag with hammer and sickle that both symbolised communism, quite similar to the flag of the Soviet Union. Their final versions prior to the dissolution of the USSR in 1991 looked like this:

Flag of Armenian SSR	Flag of Azerbaijan SSR	Flag of Byelorussian SSR
Flag of Estonian SSR	Flag of Georgian SSR	Flag of Kazakh SSR
Flag of Kirghiz SSR	Flag of Latvian SSR	Flag of Lithuanian SSR
Flag of Moldavian SSR	Flag of Russian SFSR	Flag of Tadzhik SSR
Flag of Turkmen SSR	Flag of Ukrainian SSR	Flag of Uzbek SSR

See also the Coats of Arms of the Soviet Republics.