A new fossil genus and species of the subfamily Pselaphinae (Coleoptera: Staphylinidae), dagger Cretobrachygluta laurasiensis gen et sp. nov., is described based on an exquisitely preserved specimen in mid-Cretaceous amber from northern Myanmar. The new genus possesses a series of characters diagnostic of the extant Brachyglutini: Brachyglutina (supertribe Goniaceritae), but it also exhibits several plesiomorphic traits that suggest a basal position within the tribe. The discovery of the first and oldest brachyglutine beetle in Burmese amber considerably improves our understanding of the early morphological evolution of Pselaphinae during the Mesozoic Era.