Olesya Mamchich debuted in 2005.[2] Her poems for children are taught as part of Ukrainian elementary school curriculum.[1] Her works have been translated into English, Polish, Belarusian, Georgian, Romanian, Russian, Lithuanian, Latvian and Hebrew.[1] Her texts inspired songs of the Ukrainian band OY Sound System.[3]
Mamchich organised many poem reading events at the Euromaidan protests.[2][4] She is a curator of a Ukrainian children's literature award.[1] In 2022, she received the Lesya Ukrainka Award in the Literary Works for Children and Youth category.[5]