OSG may refer to:
* Office of the
Solicitor General of the Philippines
* Office of the
Solicitor General of the United States
* Office of the
Surgeon General of the United States
*
Oklahoma State Guard, active during World War II
*
On-site generation of electrical power
*
One Scotland Gazetteer, the definitive national land, property and address dataset for Scotland
*
Open Science Grid, a worldwide collection of technological resources
*
OpenSceneGraph, a 3D graphics programming interface
*
Operational Studies Group, a publisher of wargames related primarily to the Napoleonic Wars
*
Overseas Shipholding Group
{{disambiguation