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 11th June 2018, Cllr Ossian Smyth was elected Cathaoirleach and Cllr Mary Fayne was elected Leas-Chathaoirleach.