SGI may refer to:
- Saskatchewan Government Insurance, a provincial Crown corporation that has been developed over the years into two linked operations
- Scientific Games International: see Scientific Games Corporation
- Silicon Graphics, Inc., former manufacturer of high-performance computing solutions
- Silicon Graphics International, formerly Rackable Systems, which acquired the former Silicon Graphics, Inc
- Silicon Graphics Image, a graphics file format for Silicon Graphics workstations
- Sōka Gakkai International, a Buddhist organisation
- SGI, the IATA code for Mushaf Airbase in Pakistan
- Stargate Infinity, an animated television series
- Spheroidal Graphite Iron, another name for Ductile iron
- Sustainable Governance Indicators, first published in spring 2009 and updated in 2011, analyze and compare the need for reform in Organisation for Economic Co-operation and Development (OECD) member countries, as well as each country's ability to respond to current social and political challenges
- Synthetic Genomics, Inc., a company founded in part by Craig Venter seeking to design and synthesize new life forms by genomic engineering