The UIA World Congress of Architects is an international event for architectural dialogue organised by the International Union of Architects (UIA, by its French acronym), a non-governmental organisation that unites national associations of architects from over 100 countries, representing more than one million professionals. The first UIA Congress of Architects, which also marked the institution's founding, was held in Lausanne in 1948 during the post-war reconstruction period. Since then, UIA congresses have been held every three years in a different city within a member country, serving as the organisation's main recurring event. In 2026, the Congress will be held in Barcelona, and UNESCO has consequently designated the city as the World Capital of Architecture 2026. Each Congress focuses on a key topic relevant to the profession, articulated through a central theme. Recent themes include Copenhagen 2023: "Sustainable Futures. Leave no one behind." and Rio 2020–2021: "All the worlds. Just one World." The topic for 2026 is "Becoming. Architectures for a Planet in Transition," welcoming renowned figures in contemporary architectural thought and practice for a broad and critical overview of the possible futures of architecture.
