ICG may refer to
- ICG Communications
- Illinois Central Gulf Railroad
- Impedance cardiography, a hemorheology technique for detecting the properties of the blood flow in the thorax.
- Indian Coast Guard
- Icelandic 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 Coal Group
- International Commission on Glass
- International Crisis Group, a non-profit organisation.
- Internet Capital Group
- Inversive congruential generator
- Intra-character gap (or inter-character gap) in American Morse code.
- Irish Continental Group, an Irish sea shipping firm.
- Independent Comics Group, an imprint of Eclipse Comics.