The districts of Sri Lanka are divided into administrative sub-units known as divisional secretariats. These were originally based on the feudal counties, the korales and ratas. They were formerly known as 'D.R.O. Divisions' after the 'Divisional Revenue Officer'. Later the D.R.O.s became 'Assistant Government Agents' and the Divisions were known as 'A.G.A. Divisions'. Currently, the Divisions are administered by a 'Divisional Secretary', and are known as 'D.S. Divisions'.
The 331 divisions are listed below, by district: