The Union of International Associations (UIA) is a non-profit non-governmental research institute and documentation center based in Brussels, Belgium, and operating under United Nations mandate.

The UIA is an independent research institute and a repository for current and historical information on the work of global civil society.

The UIA also supports and facilitates the work of international associations through training and networking opportunities.

[1] Then with the help of the sociologist Cyril van Overbergh they extend this research to organisations based elsewhere.

[2] After collaborating with Alfred Fried on the production of Annuaire de la Vie Internationale they produced their own edition without him.