- COMCARGRU (Commander, Carrier Group)
- COMCAT (Character-Oriented Message Catalog)
- COMCOGARDGRU (Commander, Coast Guard Group)
- COMCRUDESGRU (Commander, Cruiser Destroyer Group)
- comd (command)
- COMDCAEUR (Commander, Defense Communications Agency Europe)
- COMDESGRU (COMmander, DEStroyer GRoUp)
- COMDESRON (COMmander DEStroyer SquadRON)
- COMDEX (Computer Dealers Exposition)
- COMDT (Commandant)
- COMDT COGARD (Commandant, United States Coast Guard)
- COMDTINST (Commandant, United States Coast Guard Instruction)
- COMECON (Council for Mutual Economic Assistance (economic counterpart of the Warsaw Pact, 1949–1991))
- COMET (Children Of Many Educational Talents)
- COMEX (Commence Exercise)
- COMFAC (COMmunications FACility)
- COMFAIRWESTPAC (COMmander Fleet AIR forces, WESTern PACific)
- COMFL (Central Ontario Minor Football League)
- COMFORT (Comprehensive Observation And Monitoring For Our Richland Tots)
- COMICEDEFOR (COMmander, United States Forces, ICEland (Iceland DEFense FORces))
- COMICS ((instrumentation) COoled Mid-Infrared Camera and Spectrometer, an instrument for the Subaru Telescope)
- COMIDEASTFOR (COMmander, MIDdle EAST FORces)
- COMINEWARCOM (COMmander, MINE WARfare COMmand)
- COMINFIL (COMmunist INFILtration)
- COMINT (Communications Intelligence)
- COMJCSE (Commander, Joint Communications Support Element)
- COMJIC (Commander, Joint Intelligence Center)
- COMJSOTF (Commander, Joint Special Operations Task Force)
- COML (compaction log)
- COMLANDFOR (COMmander, LAND FORces)
- COMLANTAREACOGARD (COMmander, Coast Guard AtLANTic AREA)
- COMLANTFLT (COMmander, u.s. atLANTic FLeeT (see CINCLANTFLT))
- COMLOGGRU (COMbat LOGistics GRoUp)
- COMM (Communications receiver)
- COMMARFOR (COMmander, MARine Corps FORces)
- COMMARFORNORTH (COMmander, MARine Corps FORces North)
- COMMARFORSOC (Commander, U.S. Marine Corps Forces Special Operations Command)
- COMMDZ (COMmander, Maritime Defense Zone)
- COMMIT (Connecting Opportunities To Motivate Mend And Intervene For Teens)
- COMMO (COMMunications Officer)