Anosy is one of the 23 regions of Madagascar. It is located in the southeast of the country, on the eastern side of what was once the Toliara Province. The name Anosy means "island(s)" in Malagasy.

Due to a strategic sea route running along its coast, Anosy had been an important crossroads for the Malagasy, Muslims, and Europeans. In the mid-1600s, it was the location of the first French colonial settlement in the Indian Ocean. The region was part of the Imerina Kingdom for much of the 1800s and part of the French colony of Madagascar from the late 1800s to 1960.

Its exports have included human slaves (shipped to the Mascarene Islands and the United States in the 1700s), live cattle (exported to Réunion for almost 300 years), sisal, natural rubber, rosy periwinkle, graphite, uranothorianite, lobster, sapphires, and ilmenite. Due to its biodiversity and unique wildlife, efforts commenced in the 1980s to promote environmental conservation and tourism in the region.

The region suffers from poverty; 80% of inhabitants lack access to clean water, 16% suffer from serious respiratory illnesses, and literacy is less than 20%.

The early history of Anosy is based primarily on archeological digs in the Efaho valley, just west of Fort-Dauphin. These 11th–13th century sites on the coastal dunes were small (0.5 ha [1.2 acres] in size) and seasonal or temporary, based on the need to move to find food. Activities focused on fishing, cultivation of tubers and hunting. Iron working was also present. Trade was limited to the northeast, along the coast, and formed a very simple economic and social system.

Evidence suggests that between the 13th and 15th centuries, those living in Anosy were working chlorite schist which was exchanged through the trade network for Chinese greenware pottery. A Chinese nautical map from 1315 shows Madagascar's coastline, winds and currents. Settlements grew slightly, primarily located on the flood plains and coastal lagoons, with cultivation of sweet potatoes and further development of iron working. In the early 14th century, a Gujarat ship wrecked off the Anosy coast; it has been theorized that the stranded Gujarati went north to found the Zarabehava dynasty of Antesaka, though some scholars disagree.

In the 16th century, the Zafiraminia (descendants of the Muslim Ramini) arrived in present-day Anosy and moved into the Efaho valley after being defeated by the Antambahoaka people to the north. The Zafiraminia had lived in Madagascar from about the 13th century and had assimilated into the Malagasy population; they did not have Islamic institutions though they retained Arabic script and several socio-religious practices. The Zafiraminia introduced the use of wooden huts, owning cattle as a sign of wealth, and established a dynasty that lasted 200 years.

The Zafiraminia established a stratified society with elaborate rituals, aided by their literacy, which was viewed as a kind of magic. Their settlements were further inland, 2 to 7.5 ha (5 to 19 acres) in size, and may have been fortified with ditches and wooden palisades.