There are 40 democratically-elected public representatives on Dún Laoghaire-Rathdown County Council. The role of these Councillors is to lay down the policy framework within which the Local Authority operates. Amongst their wide and varied list of responsibilities (referred to as 'reserved functions') are to:
- Make, amend and revoke byelaws
- Adopt the annual budget
- Make or vary the County Development Plan
- Borrow Money
- Confer a civic honour on a person
Every year, the members elect a chair called An Cathaoirleach for a term of one year and a deputy chair called An Leas-Chathaoirleach from among its members. An Cathaoirleach acts as the first citizen of the County and, in addition to chairing meetings of the Local Authority, he/she also carries out ceremonial duties. When An Cathaoirleach is unavailable these duties are then carried out by An Leas-Chathaoirleach. At its annual meeting held on 13th June 2016 Cllr Cormac Devlin was elected Cathaoirleach and Cllr Shay Brennan was elected Leas-Chathaoirleach.