- UK Consortium on AIDS and International Development (1986 - )
- UK NGO AIDS Consortium
- see UK Consortium on AIDS and International Development (1986 - ) - UN
- see United Nations (1945 - ) - UN Theme Group on HIV/AIDS in China, The Joint United Nations Programme on HIV/AIDS
- UNAIDS
- see The Joint United Nations Programme on HIV/AIDS (1996 - ) - UNDP
- see United Nations Development Programme (1966 - ) - UNDP Regional HIV and Development Programme for South and North East Asia (REACH Beyond Borders) (1999 - ), United Nations Development Programme
- UNDP South East Asia HIV and Development Programme (1999 - ), United Nations Development Programme
- UNDP-SEAHIV
- see UNDP South East Asia HIV and Development Programme (1999 - ), United Nations Development Programme - UNESCAP
- see United Nations Economic and Social Commission for Asia and the Pacific (1947 - ) - UNESCO
- see United Nations Educational, Scientific and Cultural Organization (1945 - ) - UNFPA
- see United Nations Population Fund (1969 - ) - UNGASS
- see United Nations General Assembly Special Session on HIV/AIDS - UN-HABITAT
- see United Nations Human Settlement Program (1978 - ) - UNHCR
- see United Nations High Commissioner for Refugees (1950 - ) - UNICEF
- see United Nations Childrens Fund (1946 - ) - UNIFEM
- see United Nations Development Fund for Women (1976 - ) - Uniformed services
- UNISDR
- see International Strategy for Disaster Reduction (1999 - ), United Nations - United Kingdom Government, Department for International Development (1997 - )
- United Nations (1945 - )
- United Nations Childrens Fund (1946 - )
- United Nations Development Fund for Women (1976 - )
- United Nations Development Programme (1966 - )
- United Nations Development Programme, UNDP Regional HIV and Development Programme for South and North East Asia (REACH Beyond Borders) (1999 - )
- United Nations Development Programme, UNDP South East Asia HIV and Development Programme (1999 - )
- United Nations Economic and Social Commission for Asia and the Pacific (1947 - )
- United Nations Educational, Scientific and Cultural Organization (1945 - )
- United Nations General Assembly Special Session on HIV/AIDS
- United Nations High Commissioner for Refugees (1950 - )
- United Nations Human Settlement Program (1978 - )
- United Nations Office on Drugs and Crime (1997 - )
- United Nations Population Fund (1969 - )
- United Nations Research Institute for Social Development (1963 - )
- United Nations Special Session on HIV/AIDS
- see United Nations General Assembly Special Session on HIV/AIDS - United Nations, Food and Agriculture Organization of the United Nations (1945 - )
- United Nations, International Fund for Agricultural Development (1977 - )
- United Nations, International Labour Organization (1919 - )
- United Nations, International Strategy for Disaster Reduction (1999 - )
- United Nations, The Joint United Nations Programme on HIV/AIDS (1996 - )
- United Nations, United Nations Childrens Fund (1946 - )
- United Nations, United Nations Development Fund for Women (1976 - )
- United Nations, United Nations Development Programme (1966 - )
- United Nations, United Nations Economic and Social Commission for Asia and the Pacific (1947 - )
- United Nations, United Nations Educational, Scientific and Cultural Organization (1945 - )
- United Nations, United Nations High Commissioner for Refugees (1950 - )
- United Nations, United Nations Human Settlement Program (1978 - )
- United Nations, United Nations Office on Drugs and Crime (1997 - )
- United Nations, United Nations Population Fund (1969 - )
- United Nations, United Nations Research Institute for Social Development (1963 - )
- United Nations, World Bank (1944 - )
- United Nations, World Food Programme (1963 - )
- United Nations, World Health Organization (1948 - )
- The United States Agency for International Development (1961 - )
- Universal access
- see Access to treatment - The University of Melbourne, Australian International Health Institute (1998 - )
- The University of New South Wales, National Centre in HIV Epidemiology and Clinical Research (1986 - )
- The University of New South Wales, National Centre in HIV Social Research (1990 - )
- The University of New South Wales, School of Public Health and Community Medicine (2002 - )
- UNODC
- see United Nations Office on Drugs and Crime (1997 - ) - UNRISD
- see United Nations Research Institute for Social Development (1963 - ) - USAID
- see The United States Agency for International Development (1961 - ) - US-China AIDS Foundation (2003 - )