The males of the family Formicidae in the Malagasy region, including the islands of the southwest Indian Ocean (Madagascar, Mauritius, Reunion, Comoros, and Seychelles) are reviewed. A male-based synopsis of each subfamily and genera are provided. A richly illustrated male-based key to the eight subfamilies and 71 genera for which males are known are provided. Terminologies for morphology and wing cells are also reviewed. The keys are a product of three decades of collecting across the region. Despite efforts to collect males for all genera, males from four genera (Brachyponera, Chrysapace, Dicroaspis, Ochetellus) were included in the keys based on males from species collected outside the region, and males from one genus (Parvaponera) are unknown globally and not included in the key.