Oleg (Russian: Олег), Oleh (Ukrainian: Олег), or Aleh (Belarusian: Алег) is an East Slavic given name. It is a common name in Russia. The feminine form of Oleg is Olga.
- Oleg the Wise, 9th–10th-century leader and conqueror of Kievan Rus'
- Oleg Anofriyev (1930–2018), Soviet and Russian stage and screen actor, voice actor, singer, songwriter, film director, poet
- Oleg Baklanov (1932–2021), Soviet/Ukrainian politician, scientist and businessman
- Oleg Blokhin (born 1952), Ukrainian football coach
- Oleg Bryjak (1960–2015), Kazakhstani operatic bass-baritone
- Oleg Karavaychuk (1927–2016), Russian composer
- Oleg Moliboga (1953–2022), Russian volleyball player and coach
- Oleg Pashinin (born 1974), Uzbekistani footballer
- Oleg Pavlov (1970–2018), Russian writer
- Oleg Protopopov (1932–2023), Russian figure skater
- Oleg Prudius (born 1972), Ukrainian professional wrestler known by his ring name Vladimir Kozlov
- Oleg Romantsev (born 1954), Russian footballer and manager
- Oleg Salenko (born 1969), Russian-Ukrainian footballer
- Oleg Seleznyov (1959–2021), Russian politician
- Oleg Sentsov (born 1976), Ukrainian filmmaker, writer and activist
- Oleg Tabakov (1935–2018), Soviet and Russian actor
- Oleg Tverdovsky (born 1976), Ukrainian-Russian ice hockey player
- Oleg Yefremov (1927–2000), Soviet and Russian actor and producer