The hide, larder, and carpet beetles (Coleoptera: Dermestidae) are a family of mainly scavenger beetles, with numerous species such as the khapra beetle (Trogoderma granarium Everts, 1898), the black carpet beetle [Attagenus unicolor (Brahm, 1791)] and the hide beetle (Dermestes maculatus De Geer, 1774) being widely recognized as serious economic pests of stored products and museum collections. A stable classification and reliable identification of genera and species of these pests and their 1,700 relatives are of great relevance for trade restrictions, biosecurity, pest management, forensics, and biodiversity surveys. In this study, we examined and sequenced mitochondrial genomes of 477 dermestid specimens, representing all subfamilies and 90% of the globally recognized tribes and subtribes. Our study provides the most comprehensive, taxonomically verified, and vouchered resource of mitochondrial reference sequences linked to specimen images and occurrence records of pests and their relatives, enabling eDNA surveys, metabarcoding and molecular species identification. It also reconstructs the phylogeny of Dermestidae based on molecular and morphological data for the first time, thereby providing robust phylogenetic hypotheses for a stable classification system from family to genus-level. Accordingly, a revised classification of Dermestidae with formal nomenclatural changes is proposed, recognizing six subfamilies: Orphilinae, Trinodinae, Trogoparvinae subfam. nov. (type genus Trogoparvus Háva, 2001), Dermestinae, Attageninae, and Megatominae. Trinodinae is recovered towards the base of Dermestidae with three tribes: Trinodini (=Trinoparvini syn. nov.), Thylodriini, and Trichelodini. Dermestinae is the only subfamily with adults lacking a median ocellus, and it includes the tribes Thorictini stat. nov. (that is downgraded from Thorictinae), Marioutini, and Dermestini. The endemic Australian genus Derbyana Lawrence and Ślipiński was recovered within Holarctic Dermestes Linnaeus. Attageninae is strongly supported and includes the monogeneric Adelaidiini and polygenic Attagenini. Former subgenera of Attagenus Latreille, i.e., Lanorus Mulsant and Rey (= Paranovelsis Casey syn. nov.), Telopes Redtenbacher and Aethriostoma Motschulsky, are elevated to generic level. The largest clade, Megatominae, is confirmed as monophyletic and is divided into three tribes: Anthrenini, Ctesiini, and Megatomini. Megatomini is divided into three subtribes: Megatomina, Orphinina subtribe nov. (type genus Orphinus Motschulsky), and Trogodermina. Within the economically important lineage Trogodermina, Trogoderma Latreille is delimited to contain only Holarctic species including the Khapra beetle T. granarium Everts, while a Southern Hemisphere clade is here recognized as Eurhopalus Solier in Gay, 1849 (= Anthrenocerus Arrow, 1915; Myrmeanthrenus Armstrong, 1945; Neoanthrenus Armstrong, 1941; Sodaliatoma Háva, 2013; Reesa Beal, 1967 syn. nov.). A revised classification of the extant genera of Dermestidae is also provided.