- ICMB(Institute of Cell and Molecular Biology)
- ICMBC(Imperial College Medics Boat Club)
- ICME(International Council on Materials Education)
- ICMP(Internet Control Message Protocol)
- ICMR(Indian Council of Medical Research)
- ICMS(Integrated Circuit Measurement System)
- ICN(Iowa Communications Network)
- ICNAF(International Commission for the Northwest Atlantic Fisheries (became NAFO in 1978))
- ICNI(Integrated Communication, Navigation, and Identification)
- ICNIA(Integrated Communications, Navigation, and Identification Avionics)
- ICNM(International Center for New Media)
- ICO("in case of" "in care of")
- ICOA(International CBX Owners Association)
- ICOC(Indianapolis Chamber of Commerce)
- ICOD(Intelligence Cutoff Date)
- ICODE(Icfaian Council for Open and Distance Education, India)
- ICODES(Integrated Computerized Deployment System)
- ICOE(In Case Of Emergency)
- ICOFT(Institutional Conduct of Fire Trainer)
- ICOM(Input, Control, Output, And Means)
- ICON(Isotopes of Carbon, Oxygen, and Nitrogen)
- ICoTA(Intervention and Coiled Tubing Association)
- ICOUR(Irrigation Company for the Upper Regions)
- ICP(Infection control professional)
