SCG may refer to:
- SCG, the ISO 3166-1 alpha-3 code for the former union of Serbia and Montenegro, which peacefully split in 2006 into two countries
- StarCityGames.com, the world's largest Magic: The Gathering online retailer.
- SCG International Risk, a private military contractor and security firm
- Self-Changing Gears, a British company
- Seychelles Coast Guard
- Socialist Campaign Group, a left-wing grouping of UK Labour Party MPs
- Southern Connecticut Gas Company
- Summa contra Gentiles, a Christian studies book
- Superior cervical ganglion, the largest of the cervical ganglia
- Sydney Cricket Ground, a sports stadium in Sydney, Australia
- Stable Cavitation Generator, a device that creates stable but oscillating bubbles in liquids under an ultrasound and shockwave field.
- Sun City Girls, a now defunct United States experimental band.
- Siam Cement Group, the largest cement manufacturer in Thailand and patron of SCG Muangthong United