Ten strains of a new endophytic ascospore-forming, methanol-assimilating yeast were isolated from the galls induced by sawflies on the leaves of willows in the Losiny Ostrov National Park (Moscow region). Standard phenotypical tests and phylogenetic analyses of 18S rRNA gene, 5.8S-ITS gene region and 26S rRNA gene (D1/D2 domains) sequences showed that the species belongs to the genus Ogataea. We describe it as Ogataea cecidiorum and designate type culture KBP Y-3846 (= CBS 11522(T) = VKM Y-2982(T) = VKPM Y-3482(T) = MUCL 52544(T) = NCAIM Y.01965(T)) as the type strain. The new species was registered in MycoBank under MB 515233