- Els Aarne (1917–1995), born in present-day Estonia
- Evald Aav (1900–1939), born in present-day Estonia
- Juhan Aavik (1884–1982), born in present-day Estonia
- Arkady Abaza (1843–1915)
- Lev Abeliovich (1912–1985), born in present-day Lithuania
- Alexander Abramsky (1898–1985), born in present-day Ukraine
- Joseph Achron (1886–1943), born in present-day Lithuania
- Ella Adayevskaya (1846–1926)
- Nikolay Afanasyev (1820/1–1898)
- Vasily Agapkin (1884–1964)
- Alexander Alexandrov (1883–1946)
- Anatoly Alexandrov (1888–1982)
- Boris Alexandrov (1905–1994), son of Alexander
- Achilles Alferaki (1846–1919)
- Alexander Alyabyev (1787–1851)
- Anatoliy Andreyev (1941–2004)
- Iosif Andriasov (1933–2000)
- Boris Arapov (1905–1992)
- Anton Arensky (1861–1906)
- Sasha Argov (1914–1995)
- Mykola Arkas (1853–1909), born in present-day Ukraine
- Alexander Arkhangelsky (1846–1924)
- Eduard Artemyev (1937–2023)
- Nikolai Artsybushev (1858–1937)
- Vyacheslav Artyomov (born 1940)
- Boris Asafyev (1884–1949)
- Mukhtar Ashrafi (1912–1975), born in present-day Uzbekistan
- Sergei Aslamazyan (1897–1978), born in present-day Armenia
- Lera Auerbach (born 1973)
- Arseny Avraamov (1886–1944)
- Artemi Ayvazyan (1902–1975), born in present-day Armenia
- Mikhail Azanchevsky (1839–1881)
- Vytautas Bacevičius (1905–1970), born in present-day Lithuania
- Afrasiyab Badalbeyli (1907–1976), born in present-day Azerbaijan
- Vladimir Bakaleinikov (1885–1953)
- Mily Balakirev (1837–1910)
- Sergey Balasanian (1902–1982), born in present-day Turkmenistan
- Sargis Barkhudaryan (1887–1973), born in present-day Georgia
- Veniamin Basner (1925–1996)
- Kārlis Baumanis (1835–1905), born in present-day Latvia
- Sonya Belousova (born 1990)
- Maxim Berezovsky (c. 1745 – 1777)
- Anastasiya Bespalova
- Timofiy Bilohradsky (c. 1710 – c. 1782)
- Matvey Blanter (1903–1990)
- Felix Blumenfeld (1863–1931)
- Leonid Bobylev (born 1949)
- Anatoly Bogatyrev (1913–2003), born in present-day Belarus
- Nikita Bogoslovsky (1913–2004)
- Alexander Borodin (1833–1887)
- Sergei Bortkiewicz (1877–1952), born in present-day Ukraine
- Dmitry Bortniansky (1751–1825), born in present-day Ukraine
- Rostislav Grigor'yevich Boyko (1931–2002)
- Yevgeny Brusilovsky (1905–1981)
- Vitaly Bujanovsky (1928–1993)
- Pavel Bulakhov (1824–1875), brother of Pyotr
- Pyotr Bulakhov (1822–1885), brother of Pavel
- Revol Bunin (1924–1976)
- Mutal Burhonov (1916–2002), born in present-day Uzbekistan
- Dmitry Kabalevsky (1904–1987)
- Murad Kajlayev (born 1931)
- Vasily Kalafati (1869–1942)
- Vasily Kalinnikov (1866–1901)
- Sandor Kalloś (born 1935)
- Alfrēds Kalniņš (1879–1951), born in present-day Latvia
- Jānis Kalniņš (1904–2000), son of Alfrēds, born in present-day Latvia
- Artur Kapp (1878–1952), born in present-day Estonia
- Eugen Kapp (1908–1996), son of Artur, born in present-day Estonia
- Villem Kapp (1913–1964), nephew of Artur, born in present-day Estonia
- Nikolai Kapustin (1937–2020)
- Nikolai Karetnikov (1930–1994)
- Daniil Kashin (1769–1841)
- Leokadiya Kashperova (1872–1940)
- Yuri Kasparov (born 1955)
- Alexander Kastalsky (1856–1926)
- Yakov Kazyansky (born 1948)
- Nikolay Kedrov Jr. (1905–1981), son of Nikolay Kedrov Sr.
- Nikolay Kedrov Sr. (1871–1940)
- Ivan Kerzelli (fl. 18th century)
- Aram Khachaturian (1903–1978), born in Georgia to an Armenian family
- Karen Khachaturian (1920–2011), nephew of Aram
- Ivan Khandoshkin (1747–1804)
- Yuri Khanon (born 1965)
- Tikhon Khrennikov (1913–2007)
- Igor Khudolei (1940–2001)
- Victor Kissine (born 1953)
- Dmitri Klebanov (1907–1987), born in present-day Ukraine
- Alexander Knaifel (1943–2024)
- Lev Knipper (1898–1974), born in present-day Georgia
- Vladimir Kobekin (born 1947)
- Mikhail Kollontay (born 1952)
- Lev Konov (born 1952)
- Yelena Konshina (born 1950)
- Alexander Kopylov (1854–1911)
- Grigoriy Korchmar (born 1947)
- Arseny Koreshchenko (1870–1921)
- Nikolai Korndorf (1947–2001)
- Viktor Kosenko (1896–1938)
- Alexander Koshetz (1875–1944), born in present-day Ukraine
- Nikita Koshkin (born 1956)
- Serge Koussevitzky (1874–1951)
- Osip Kozlovsky (1757–1831)
- Pylyp Kozytskiy (1893–1960), born in present-day Ukraine
- Cyrillus Kreek (1889–1962), born in present-day Estonia
- Alexander Krein (1883–1951)
- Vyacheslav Kruglik
- Yevgeny Krylatov (1934–2019)
- Andrei Krylov (born 1961)
- Muslim Magomayev (1885–1937), born in present-day Azerbaijan
- Heorhiy Maiboroda (1913–1992), born in present-day Ukraine
- Katerina Maier (fl. c. 1800)
- Nina Makarova (1908–1976)
- Leonid Malashkin (1842–1902)
- Dmitry Malikov (born 1970)
- Witold Maliszewski (1873–1939), born in present-day Ukraine
- Igor Markevitch (1912–1983), born in present-day Ukraine
- Mykola Markevych (1804–1860), born in present-day Ukraine
- Vladimir Martynov (born 1946)
- Vladimir Matetsky (born 1952)
- Mikhail Matinsky (1750 – c. 1820)
- Igor Matvienko (b.1960)
- Mikhail Matyushin (1861–1934)
- Samuel Maykapar (1867–1938)
- Jānis Mediņš (1890–1966), born in present-day Latvia
- Nikolai Medtner (1880–1951)
- Yuliy Meitus (1903–1997), born in present-day Ukraine
- Romanos Melikian (1883–1935), born in present-day Armenia
- Emilis Melngailis (1874–1954), born in present-day Latvia
- Ion Melnik (1935–2018)
- Zhanneta Metallidi (1934–2019)
- Moses Milner (1886–1953)
- Emil Młynarski (1870–1835), born in present-day Lithuania
- Boris Mokrousov (1909–1968)
- Kirill Molchanov (1922–1982)
- Fred Momotenko (born 1970)
- Alexander Mordukhovich (born 1946)
- Alexander Mosolov (1900–1973)
- Veli Mukhatov (1916–2005), born in present-day Turkmenistan
- Vano Muradeli (1908–1970), born in present-day Georgia
- Modest Mussorgsky (1839–1881)
- Mansur Muzafarov (1902–1966)
- Nikolai Myaskovsky (1881–1950)
- Mart Saar (1882–1963), born in present-day Estonia
- Leonid Sabaneyev (1881–1968)
- Martha von Sabinin (1831–1892)
- Tolibjon Sadikov (1907–1957), born in present-day Uzbekistan
- Vasily Safonov (1852–1918)
- Niescier Sakałoŭski (1902–1950), born in present-day Belarus
- Vadim Salmanov (1912–1978)
- Lazare Saminsky (1882–1959)
- Huseyngulu Sarabski (1879–1945), born in present-day Azerbaijan
- Joseph Schillinger (1895–1943)
- Alfred Schnittke (1934–1998)
- Eduard Schütt (1856–1933)
- Alexander Scriabin (1872–1915)
- Julian Scriabin (1908–1919), son of Alexander
- Tatyana Sergeyeva (born 1951)
- Alexander Serov (1820–1871)
- Valentina Serova (1846–1924)
- Vladimir Shainsky (1925–2017)
- Masguda Shamsutdinova (born 1955)
- Yuri Shaporin (1887–1966), born in present-day Ukraine
- Adrian Shaposhnikov (1888–1967)
- Rodion Shchedrin (born 1932)
- Nikolai Shcherbachov (1853–1922)
- Vladimir Shcherbachov (1889–1952)
- Vissarion Shebalin (1902–1963)
- Boris Sheremetev (1822–1906)
- Baluan Sholak (1864–1919), born in present-day Kazakhstan
- Dmitri Shostakovich (1906–1975)
- Andriy Shtoharenko (1902–1992), born in present-day Ukraine.
- Jean Sibelius (1965–1957), born in present-day Finland.
- Nikolaï Sidelnikov (1930–1992)
- Alexander Siloti (1863–1945)
- Juhan Simm (1885–1959), born in present-day Estonia
- Yekaterina Sinyavina (died 1784)
- Gregory Skovoroda (1722–1794)
- Ādolfs Skulte (1909–2000), born in present-day Latvia
- Nicolas Slonimsky (1894–1995)
- Sergei Slonimsky (1932–2020), nephew of Nicolas
- Dmitri Smirnov (1948–2020)
- Vladimir Sokalsky (1863–1919)
- Ivan Sokolov (born 1960)
- Nikolay Sokolov (1859–1922)
- Mikhail Sokolovsky (1756 – after 1795)
- Nicolai Soloviev (1846–1916)
- Vasily Solovyov-Sedoi (1907–1979)
- Antonio Spadavecchia (1907–1977)
- Alexander Spendiaryan (1871–1928)
- Alexei Stanchinsky (1888–1914)
- Maximilian Steinberg (1883–1946), born in present-day Lithuania
- Yakiv Stepovy (1883–1921), born in present-day Ukraine
- Kyrylo Stetsenko (1882–1922), born in present-day Ukraine
- Igor Stravinsky (1882–1971)
- Peeter Süda (1883–1920), born in present-day Estonia
- Grikor Suni (1876–1939), born in present-day Armenia
- Viktor Suslin (1942–2012)
- Yevgeny Svetlanov (1928–2002)
- Georgy Sviridov (1915–1998)