Records of Depressariidae species collected in the Altai Republic (Russia) in 2014–2019 are presented. Agonopterix kyzyltashensis sp. nov., A. ustjuzhanini sp. nov., and Depressaria paraleucocephala sp. nov. are described as new for science. Depressaria leucocephala Snellen, 1884 is deleted from the list of Altaic Depressariidae due its previous confusion with D. paraleucocephala sp. nov. Agonopterix rimulella (Caradja, 1920) sp. restit. is removed from synonymy with Agonopterix liturosa (Haworth, 1811). Exaeretia fuscogriseella Hannemann, 1990 syn. nov. is synonymised with E. indubitatella (Hannemann, 1971). Agonopterix feruliphila Millière, 1866 syn. nov. is transferred from synonymy with Agonopterix thapsiella (Zeller, 1847) to synonymy with Agonopterix adspersella (Kollar, 1832). Provisional list of related taxa of the Agonopterix adspersella group is given. Within Russian fauna, Depressaria altaica Zeller, 1854 was presented only from the Altai Republic, namely because the type specimens were recorded in the Altai. However, type locality is the Kazakh Altai, and D. altaica should be removed from checklist of the Altai Republic. At the same time, we present the first reliable records of D. altaica from southern Ural as a new species for Russia. The first reliable record of Agonopterix putridella ([Denis & Schiffermüller], 1775) for Russia is presented. Exaeretia allisella Stainton, 1849, Agonopterix anticella (Erschoff, 1877), Agonopterix bipunctosa (Curtis, 1850), Agonopterix rimulella, Depressaria sibirella Lvovsky, 1981, D. falkovitshi Lvovsky, 1990, D. libanotidella Schläger, 1848, and D. fuscovirgatella Hannemann, 1967 are new for the Altai Republic. In addition, Exaeretia mongolicella (Christoph, 1882) was found as new for the Tuva Republic. In total, 36 species of the studied family are known from the Altai Republic to date. Figures of all species new for the Altai Republic and the Tuva Republic are presented. Newly described species are figured in detail including their genitalia.