CIG could stand for:
- Certified Interpretive Guide, credentials in language interpretation issued by the National Association for Interpretation (NAI)
- The IEEE Conference on Computational Intelligence and Games, an annual conference on computational intelligence research related to game applications
- NYSE: CIG, the stock symbol for Companhia Energetica de Minas Gerais S.A.
- A colloquial term for a cigarette
- The Canadian Improv Games, an annual nation-wide Improvisation competition for high school students in Canada
- Confederación Intersindical Galega (Galician InterTrade Union Confederation) is a Galician Trade union with the legal status of more representative trade union in Spain
- Columbia Insurance Group, a private US insurance company
- Corpus Inscriptionum Graecarum (Berlin, 1825–1877), the first attempt at a standard corpus of the Greek inscriptions of Antiquity.
- Commonwealth Industrial Gases Ltd, a former industrial gas company in Australia, now BOC Australia
- Computational Infrastructure for Geodynamics, an organization that develops and maintains open-source software for computational geophysics.
- IATA airport code for Craig-Moffat Airport
- Cig, a village in Tăşnad Town, Satu Mare County, Romania
- Center for Integrative Genomics
- Central Intelligence Group, predecessor to the Central Intelligence Agency (CIA) in 1946–1947.
- 4-CIG, a British Rail Class 421 electric multiple unit train used on the Southern Region
- Career Integration Grants, part of Marie Curie Actions European research grants