ICG may refer to
- ICG Communications
- Illinois Central Gulf Railroad
- Impedance cardiography, is a hemorheology technique for detecting the properties of the blood flow in the thorax
- Indian Coast Guard
- Indocyanine green
- Institute of Cosmology and Gravitation, University of Portsmouth, England
- Intelligence Collection Group, part of the United Kingdom's Defence Intelligence Staff
- Intermediate Capital Group, a private equity and mezzanine capital firm based in London
- International Children's Games, an International Olympic Committee-sanctioned sport event held every year
- International Crisis Group, a non-profit organisation
- Internet Capital Group
- Inversive congruential generator
- Irish Continental Group, an Irish sea shipping firm.