CIG could stand for:

• Cambridge Information Group, a privately held global investment firm focusing on information services, education and technology
• 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
• Central Intelligence Group, the predecessor to the Central Intelligence Agency, active between 1946 and 1947
• Cloud Imperium Games, a PC game software developer
• CIG, New York Stock Exchange stock symbol for Companhia Energetica de Minas Gerais S.A.

• The IEEE Conference on Computational Intelligence and Games, an annual conference on computational intelligence research related to game applications
• Cig, a colloquial term for a cigarette
• The Canadian Improv Games, an annual nationwide Improvisation competition for high school students in Canada
• Corpus Inscriptionum Graecarum (Berlin, 1825–1877), the first attempt at a standard corpus of the Greek inscriptions of Antiquity
• 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
• Copper indium gallium selenide solar cells, a kind of a flexible, thin film solar cell
• Career Integration Grants, part of Marie Curie Actions European research grants
• Converter interfaced generation
• CIG, an abbreviation for the Corpus Inscriptionum Graecarum a collection of ancient Greek inscriptions.