[33][34] The organisation's work programme focuses on:[2] UCLG's origins go back to 1913, when the Union Internationale des Villes (UIV) was set up at the International Congress of the Art of Building Cities and Organising Community Life in Ghent, Belgium.

The United Towns Organisation (UTO) (French: Fédération mondiale des cités unies (FMCU)) was set up in 1957 in Aix-les-Bains, France.

[38] It was initially known as the World Federation of Twin Cities (French: Fédération mondiale des villes jumelées).

[39] The constituent Congress of Metropolis was held in Montreal in April 1985, and was attended by 14 founding member cities:Abidjan, Addis Ababa, Barcelona, Buenos Aires, Cairo, Colombo, Ile-de-France, London, Los Angeles, Mexico, Montreal, New York, Tokyo and Turin.

[40] The united organization started under the leadership of its founding President Bertrand Delanoë, mayor of Paris, serving two three-year terms (2004-2010) and continued under Kadir Topbaş of Istanbul (2010-2016).

Following the UCLG World Congress and World Summit of Local and Regional Leaders held in Daejeon in October 2026, the UCLG leadership came to an agreement to develop a collegial Presidency, with a rotating President for a mandate of one year, as follows: Carolina Cosse, Mayor of Montevideo, year 1: from the Daejeon Congress to the end of 2023.

Current UCLG Secretary-General is Emilia Saiz, who was named in December 2017 to replace outgoing Josep Roig.

[56] UCLG facilitates the Global Taskforce of Local and Regional Governments (GTF),[57] a coordination and consultation mechanism that brings together the major international networks of local governments to undertake joint advocacy work relating to global policy processes.

The United Nations Advisory Committee of Local Authorities (UNACLA) was established by the UN Habitat Governing Council Resolution 17/18 of 1999 as an advisory body to strengthen the dialogue of the UN System with local authorities in relation to the implementation of the Habitat Agenda.