Aphids (Hemiptera, Aphidoidea) represent a diverse group of sap-feeding insects of considerable ecological and economic importance. The Iranian aphid fauna has been the subject of numerous studies, yet new records continue to emerge due to the country’s diverse climates and habitats. In the present study, three aphid species are recorded from Iran for the first time: Brachyunguis calotropicus Menon & Pawar, 1958, Dysaphis atina Ghosh, Basu & Raychaudhuri, 1969, and Metopolophium montanum Hille Ris Lambers, 1966. Detailed morphological characteristics, host plant associations, and biometric data are provided for each species. A redescription of B. calotropicus is presented based on Iranian material, clarifying its morphological features. For M. montanum, the biometric data of the Iranian population extend the ranges in the original description, and an amendment to the “Key to apterae on Rosa” in Aphids on the World’s Plants is proposed. With these additions, the number of aphid species recorded from Iran increases from 576 to 579, further highlighting the underexplored diversity of the Iranian aphid fauna and the importance of continued faunistic and taxonomic research.