This paper presents a Catalogue of oribatid mites (Acari, Oribatida) recorded from the Malay Archipelago covering 113 years from 1905 to the end of 2018. The Malay Archipelago comprises countries located in the maritime area of Southeast Asia between the Indian and Pacific Oceans, viz., Malaysia, Singapore, Brunei, Indonesia, East Timor and the Philippines. Information compiled for each species includes references to the original description, subsequent re-combinations of specific name with other genera, and junior synonyms, if any, as well as the type locality, type habitat, later recorded habitats, and geographic distribution within and outside the Malay Archipelago. A historical review of explorations and taxonomic studies on oribatids in the various countries is also provided. A total of 1,030 valid species including subspecies and 6 doubtful species have been recorded from the Malay Archipelago from 1905 to 2018. The valid species belong to 323 genera, 98 families and 34 superfamilies in all of the five infraorders and two hyporders of the Suborder Oribatida. Among the component countries, the Philippines has the highest number of records at 513, followed by Indonesia including Kalimantan and excluding the Moluccas and Irian Barat on New Guinea Island (402), Malaysia including Sabah and Sarawak (250), Brunei (64), and Singapore (28), while not a single species is currently known from East Timor. Most of the species known from Malaysia come from its two provinces (Sabah and Sarawak) in Borneo Island with 190, or more than twice that on Peninsular or West Malaysia with 77 species. On the whole, Borneo Island which is home for three countries has 235 recorded species with Sabah and Sarawak having 190, Brunei 64, and Kalimantan only 18 species. Aside from Borneo, the better explored islands, in descending order of records, are Luzon (346), Java (261), Samar (182), Mindanao (178), Leyte (112), Polillo (105), Bali (99), and Sumatra (82), and the peninsular part of Malaysia (78), while the relatively large island of Sulawesi has only 13 species records. Endemism to the individual countries ranges from 36.1–60.7%, the highest of which are Singapore (60.7%) and Brunei (57.8%). The relatively better known and bigger countries have lower rates of endemism—47.4% for the Philippines, 46.8% for Malaysia, whereas Indonesia, with the largest land area and earliest records, has the lowest rate of 36.1%. Overall, 608 species or 59.0% of the total fauna of the Malay Archipelago are known so far only from this region.
