Before 1925, the chair of each rural district council sat as an ex officio member of the council.[5] Under the Local Government Act 1925, rural district councils in Ireland were abolished and their functions transferred to the county councils.[6] In County Cavan, these were the districts of Bailieborough, Bawnboy, Castlerahan, Cavan, Enniskillen No. 2, and Mullaghoran.[7] The number of members of the county council increased from 20 to 32.[8][9][10]
In 1942, in an order under the Local Government Act 1941, the council was reduced to 25.[11][12] This figure was restated by the Local Government Act 2001.[13]
In 2014, following a recommendation of a Local Electoral Area Boundary Committee, the council was reduced to 18 seats.[14] This was implemented by the Local Government Reform Act 2014.[15] Under the same act, all town councils in Ireland were abolished and their functions transferred to the county councils. In County Cavan, these were the town councils of Belturbet, Cavan, and Cootehill.[16] It also provided that the county be divided into municipal districts to administer council business at a local level.
^Local Government (Ireland) Act 1898, s. 3: Additional members and chairman and vice-chairman of county council, and constitution of chairman as justice (61 & 62 Vict., c. 37 of 1898, s. 3). Enacted on 12 August 1898. Act of the UK Parliament. Retrieved from Irish Statute Book.
^Local Government Reform Act 2014, s. 24: Dissolution of town councils and transfer date (No. 1 of 2014, s. 24). Enacted on 27 January 2014. Act of the Oireachtas. Retrieved from Irish Statute Book on 21 May 2022.
^Local Government Act 1991 (Regional Assemblies) (Establishment) Order 2014, Schedule 3 (S.I. No. 573 of 2014). Signed on 16 December 2014. Statutory Instrument of the Government of Ireland. Retrieved from Irish Statute Book on 19 January 2022.
^County of Cavan Local Electoral Areas and Municipal Districts Order 2018 (S.I. No. 611 of 2018). Signed on 19 December 2018. Statutory Instrument of the Government of Ireland. Archived from the original on 23 January 2020. Retrieved from Irish Statute Book on 30 January 2019.