During a survey of tydeid mites associated with plants in southern Sweden, several species new to science were found, of which six belonging to the genus Tydeus are described here. T. nytebodensis n.sp. was collected from lichens on twigs of Picea abies; T. parainflatus n.sp. was found on leaves of Corylus avellana, and Prunus padus; T. octomaculatus n.sp. from lichens and moss on ground; T. caputoperio n.sp. from grasses and lichens (Cladonia sp.) on ground; T. exiguelitteratus n.sp. from bark of fallen tree, and lichens on branches on ground; and T. danielssoni n.sp. from grasses and bark from a dead pine tree, and moss layer on ground. Lorryia polita Kuznetzov, 1975, L. danuta Karmierski, 1978, Retetydeus catenulata Thor, 1931, and Paralorryia maga Kuznetzov, 1973, are transferred to the genus Tydeus. The male of T. polita is described for the first time. Six species are reported new to Sweden. A key to females of the twelve species so far known to Sweden is given.