CIG
- Cambridge Information Group
- Canadian Improv Games
- Cemig
- Central Intelligence Group
- Chief of the General Staff
- Cloud Imperium Games
- Columbia Insurance Group
- Computational Infrastructure for Geodynamics
- Confederación Intersindical Galega
- Converter interfaced generation
- Copper indium gallium selenide solar cells
- Corpus Inscriptionum Graecarum
- Craig-Moffat Airport
- IEEE Conference on Computational Intelligence and Games
- Marie Curie Actions
- Tăşnad