The Agusan del Sur Provincial Board is the Sangguniang Panlalawigan (provincial legislature) of the Philippine province of Agusan del Sur.

The members are elected via plurality-at-large voting: the province is divided into two districts, each sending five members to the provincial board; the electorate votes for five members, with the five candidates with the highest number of votes being elected.

The vice governor is the ex officio presiding officer, and only votes to break ties.

The vice governor is elected via the plurality voting system province-wide.

An additional three ex officio members are the presidents of the provincial chapters of the Association of Barangay Captains, the Councilors' League, and the Sangguniang Kabataan.