- GAA
- see Global AIDS Alliance (2001 - ) - Gay men
- see Men who have sex with men - GAYa NUSANTARA
- GBC
- see Global Business Coalition on HIV/AIDS, Tuberculosis and Malaria (1997 - ) - GCM
- see Global Campaign for Microbicides (1998 - ) - GCWA
- see Global Coalition on Women and AIDS (2004 - ) - Gender and HIV/AIDS
- Gender Relations Centre (1992 - ), The Australian National University
- Global AIDS Alliance (2001 - )
- Global Business Coalition on HIV/AIDS, Tuberculosis and Malaria (1997 - )
- Global Campaign for Microbicides (1998 - )
- Global Coalition on Women and AIDS (2004 - )
- The Global Fund to Fight AIDS, Tuberculosis and Malaria (2001 - )
- Global Health Council, Inc. (1972 - )
- Global HIV Prevention Working Group (2002 - )
- Global Network of People Living with HIV/AIDS
- Global Youth Coalition on HIV/AIDS (2004 - )
- GMS
- see Greater Mekong Subregion - GNP+
- see Global Network of People Living with HIV/AIDS - Governance
- Greater Mekong Subregion
- GUAHAN Project
- Guam, Territory of Guam
- Guam HIV/AIDS Network
- see GUAHAN Project - Guttmacher Institute
- see Alan Guttmacher Institute (1968 - )