(USSR, acronym for Ukrayinskaya Sotsialisticheskaya Sovetskaya Respublika (Ukrainian Socialist Soviet Republic) in the Russian language).

The Soviet Union and two of its republics (Ukraine and Byelorussia) all became members of the nascent United Nations (UN) in 1945.

[2] To comply, the Ukrainian Soviet authorities dropped the lettering and added an azure horizontal stripe (1⁄3 of the width).

[2] While the Soviet flag was flown in the later months of 1991, even after the failed coup d'état, the blue and yellow flag, even though it was a criminal offense under the Soviet law, was raised spontaneously throughout Ukraine by local activists between 14 March 1990 beginning at town of Stryi until the country's independence on 24 August 1991.

Despite the ban, the flags of the Ukrainian SSR have been used in the some areas occupied by Russia during the Russian invasion of Ukraine.