The North/South Ministerial Council (NSMC) (Irish: An Chomhairle Aireachta Thuaidh-Theas, Ulster-Scots: North South Meinisterlie Council)[1] is a body established under the Good Friday Agreement to co-ordinate activity and exercise certain governmental powers across the whole island of Ireland.

[2] When the Northern Ireland Assembly is suspended, responsibility for areas of co-operation fall to the British-Irish Intergovernmental Conference.

[3] The council is supported by a standing joint secretariat, consisting of members of the civil services of both Northern Ireland and the Republic.

The council also has occasional meetings in an "institutional" format to consider other business and technical matters, such as appointments to boards.

Originally, a new jointly owned agency, Lights Agency, was intended to replace the Commissioners of Irish Lights, which is funded from the UK Department for Transport-managed General Lighthouse Fund to provide coastal aids to navigation throughout the island of Ireland.