Olesya (Ukrainian and Russian: Олеся), may also be spelt Olessia or Olesia, is a feminine given name.

Olesya is a Slavonic name that derives from a word "lyess" (Ukrainian "ліс", Russian "лес" - forest) and means "a girl from the forest", "a girl living in the forest". A different version of the origin of the name states that Olesya is a variant of the name Alexandra, and thus acquires the meaning of "protector". The names Alesya and Lesya can be considered variants of Olesya.

Notable people with the name include:

• Olesya Aliyeva (b. 1977), Russian alpine skier
• Olesya Babushkina (b. 1989), Belarusian gymnast
• Olesya Bakunova (b. 1980), Belarusian sprint canoer
• Olesya Barel (b. 1960), Russian basketball player
• Olesya Belugina (b. 1984), Russian gymnast
• Olesya Chumakova (b. 1981), Russian middle-distance runner
• Olesya Dudnik (b. 1974), Ukrainian gymnast and coach
• Olesya Forsheva (b. 1979), Russian athlete
• Olesya Hudyma (b. 1980), Ukrainian artist, poet and journalist
• Olesya Kurochkina (b. 1983), Russian football player
• Olesya Mashina (b. 1987), Russian footballer
• Olesya Nazarenko (born 1976), amateur wrestler, judoka and sambo player from Turkmenistan
• Olesya Nurgalieva (b. 1976), Russian ultramarathon runner
• Olesya Povh (b. 1987), Ukrainian sprinter
• Olesya Rostovskaya (b. 1975), Russian composer, theremin player, carillonneur, organist, Russian zvon bell-ringer
• Olesya Rulin (b. 1986), Russian-American actress
• Olesya Stefanko (b. 1988), Ukrainian beauty pageant winner
• Olesya Syreva (b. 1983), Russian athlete
• Olesya Velichko (b. 1981), Russian modern pentathlete
• Olesya Vladykina (b. 1988), Russian Paralympic swimmer
• Olesya Truntaeva (b. 1980), Russian footballer
• Olesya Zabara (b. 1982), Russian triple jumper
• Olesya Zamula (b. 1984), Azerbaijani wrestler
• Olesya Zykina (b. 1980), Russian athlete