Common alder or Black alder, Alnus glutinosa (L.) Gaertn. (Betulaceae), is a native tree widely distributed in Europe, western Asia and North Africa. It is both a pioneering species that supports complex communities and a valuable timber resource. Eriophyoid mites (Acari: Eriophyoidea) are obligate phytophagous mites with high host specificity. Most eriophyoid mites are vagrant and cause little or no obvious damage but some cause economically important harm. Some species transmit plant viruses and others are potential biological control agents of weeds. Eriophyoid mites cause different types of symptoms on alder, such as galls, erinea and blisters. More than thirty eriophyoid species have been reported from Alnus spp. worldwide, but there are only two species known from Turkiye. This study aimed to further the knowledge of eriophyoid mites associated with A. glutinosa in Turkiye. Leaf samples were collected from alder trees in twenty-one provinces of Türkiye between 2021 and 2023. At each location, about 20 shoots around 30-40 cm long were randomly collected, and both sides of the leaves were checked under a stereomicroscope. Eriophyoid mites obtained from the samples were cleared with lactophenol and mounted in Hoyer’s medium for identification. Eight eriophyoid species were found on A. glutinosa in Turkiye, including one new species, Aceria n. sp. (Eriophyidae). Sierraphytoptus alnivagrans Keifer, 1939 (Phytoptidae), Eriophyes inangulis (Nalepa, 1919), Tegnacus marinalni (Keifer, 1939), Tegonotus trouessarti Nalepa, 1890 (Eriophyidae) and Diptacus genusetosus Gol, Sadeghi Namaghi & de Lillo, 2018 (Diptilomiopidae) are new records for Turkiye, and Acalitus brevitarsus (Fockeu, 1890) and Eriophyes laevis (Nalepa, 1889) (Eriophyidae) are known from Turkiye. This study has progressed the understanding of the diversity, distribution and ecology of the eriophyoid mites associated wit A. glutinosa in Turkiye. This research was funded by The Scientific and Technological Research Council of Turkiye (TUBITAK # 220N174) and the Zoological Institute of Russian Academy of Sciences (ZIN RAS # 125013001089-0).