The Adjarian Autonomous Soviet Socialist Republic (Adjarian ASSR or Adzhar ASSR; Georgian: აჭარის ავტონომიური საბჭოთა სოციალისტური რესპუბლიკა, romanized: ach'aris avt'onomiuri sabch'ota sotsialist'uri resp'ublik'a; Russian: Аджарская Автономная Советская Социалистическая Республика, romanized: Adzharskaya Avtonomnaya Sovetskaya Sotsialisticheskaya Respublika) was an autonomous republic of the Soviet Union within the Georgian SSR, established on 16 July 1921.

After a temporary occupation by Turkish and British troops in 1918–1920, Ajaria was reunited with Georgia in 1920.

A brief military conflict in March 1921 prompted the government in Ankara to cede the territory to Georgia as a consequence of Article VI of the Treaty of Kars, with the condition for autonomy to be provided for the Muslim population.

Nonetheless, Islam within the new republic, as elsewhere in the Soviet Union and in common with Christianity, was persecuted and repressed.

1918–24  Turkestan3 1918–41  Volga German4 1919–90  Bashkir 1920–25  Kirghiz2 1920–90  Tatar 1921–91  Adjarian 1921–45  Crimean 1921–91  Dagestan 1921–24  Mountain 1921–90  Nakhichevan 1922–91  Yakut 1923–90  Buryat1 1923–40  Karelian 1924–40  Moldavian 1924–29  Tajik 1925–92  Chuvash5 1925–36  Kazakh2 1926–36  Kirghiz 1931–92  Abkhaz 1932–92  Karakalpak 1934–90  Mordovian 1934–90  Udmurt6 1935–43  Kalmyk 1936–44  Checheno-Ingush 1936–44  Kabardino-Balkarian 1936–90  Komi 1936–90  Mari 1936–90  North Ossetian 1944–57  Kabardin 1956–91  Karelian 1957–92  Checheno-Ingush 1957–91  Kabardino-Balkarian 1958–90  Kalmyk 1961–92  Tuvan 1990–91  Gorno-Altai 1991–92  Crimean