Proctotydaeus (Acari: Iolinidae) species live in bird nests, insect colonies, plants and barn straw, and comprise 17 species belonging to four subgenera. Here, we report three new species of Proctotydaeus mites living inside stingless bee colonies in Brazil. Proctotydaeus (Neotydeolus) lasaroi Da-Costa, Rodighero & Ferla sp. nov.,Proctotydaeus (Oriolella) dorsoreticulatus Da-Costa, Rodighero & Ferla sp. nov. and Proctotydaeus (Oriolella) quadrifasciatae Da-Costa, Rodighero & Ferla sp. nov. are described and illustrated based on specimens collected from three species of stingless bees in the state of Rio Grande do Sul, Brazil.