Amboasary Sud (Amboasary Atsimo) is a town in Anosy, Madagascar. It is the main town of Amboasary Sud District. It has a population of 45,989 in 2018.
It is located at the Mandrare River which since 1957 is crossed by a steel bridge of 414m was built, that was designed by Anciens Ets Eiffel. It is situated approximately 75 km from Fort-Dauphin and 35 km from Ambovombe.
The economy of the town is dominated by sisal plantations and 3 transforming companies.
The Anony Lake (2 300 ha) at 17 km south from Amboasary Sud and the Ranofotsy Lake (500ha).
The town is linked to Fort-Dauphin by the National road 13 (73 km).