ICN is a three letter abbreviation that may refer to:
- IATA Code for Incheon International Airport near Seoul, South Korea
- Educational institutes:
- ICN Business School, French graduate business school in Nancy.
- UCL Institute of Cognitive Neuroscience, an interdisciplinary grouping of physicians and scientists that is part of University College London
- Associations, congresses and organisations (various):
- International Competition Network a regulators association.
- International Council of Nurses, a federation of national nursing associations
- Iowa Communications Network, an Iowa state agency
- Computing and digital communications:
- The Integrated Computing Network maintained by the Los Alamos National Laboratory
- The Illinois Century Network, an operation by the Illinois Department of Central Management Services
- Information-centric networking
- Science and medicine:
- Iodine cyanide, a pseudohalogen with formula ICN or CNI
- Inclusion conjunctivitis of the newborn in medicine
- Intensive care nursery
- International Code of Nomenclature for algae, fungi, and plants in botany
- Valeant Pharmaceuticals International, formerly named "ICN Pharmaceuticals", and prior to that "ICN Radiochemicals"
- Rail transportation:
- The ICN (Intercity-Neigezug), a Swiss Intercity Tilting Train
- The ICN, a Croatian Tilting Train
- Independent Catholic News, a Catholic news website
- The iCN range of GPS Navigation products from Navman