GSO may refer to:
Organizations GCC Standardization Organization, of the Gulf Cooperation Council General Statistics Office of Vietnam Golden State Overnight, former name of American logistics company GLS-US Government Shipping Office, of the Government of Pakistan Grassroots Support Organization GSO Capital Partners, an American asset management firm
Orchestras Gamer Symphony Orchestra at the University of Maryland, US Gothenburg Symphony Orchestra, Sweden Greenville Symphony Orchestra, South Carolina, US Guangzhou Symphony Orchestra, China
Science and mathematics Gadolinium oxyorthosilicate, a type of scintillating inorganic crystal Generic segmentation offload, in computer networking Geosynchronous orbit, an orbit around Earth of a satellite Gram-Schmidt orthogonalization, in mathematics GSO projection, in superstring theory
Other uses General Staff Officer GSO Stadium, a former stadium in Limassol, Cyprus Piedmont Triad International Airport (IATA and FAA LID codes), North Carolina, US Southwest Gbaya language (ISO 639-3 code)