- 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)
- Comm. Prec.(Commemoratio Praecedentis ("Commemoration of the preceding feast" Breviary))
- Comm. Seq.(Commemoratio Sequentis ("Commemoration of the following feast" Breviary))
- COMMZ(Communications Zone (military))
- COMNAV(Committee for European Airspace Coordination Working Group on COMmunications and NAVigation Aids)
- COMNAVAIRFOR(COMmander, NAVal AIR FORces)
- COMNAVAIRLANT(COMmander, NAVal AIR forces, atLANTic)
- COMNAVAIRPAC(COMmander, NAVal AIR forces, PACific)
- COMNAVAIRSYSCOM(COMmander, NAVal AIR SYStems COMmand)
- COMNAVCOMTELCOM(COMmander, NAVal COMputer and TELecommunications COMmand)
- COMNAVELEXSYSCOM(COMmander NAVal ELEctronics SYStems COMmand)
- COMNAVFOR(COMmander, NAVy FORces)
- COMNAVMETOCCOM(COMmander, NAVal METeorology and OCeanography COMmand)
- COMNAVSEACOMBATSYSENGSTA(COMmander, NAVal SEA COMBAT SYStems ENGineering STAtion)
- COMNAVSEASYSCOM(COMmander, NAVal SEA SYStems COMmand)
- COMNAVSECGRP(COMmander, United States NAVy SECurity GRouP)
- COMNAVSECGRU(COMmander, NAVal SECurity GRoUp)
- COMNAVSURFLANT(COMmander, NAVal SURface Force, AtLANTic)
- COMNAVSURFPAC(COMmander, NAVal SURface Force, PACific)
- COMO(Computer Model)
- Comp(B Composition B)
- COMPACAF(COMmander, PACific Air Forces)
- COMPACAREACOGARD(COMmander, Coast Guard PACific AREA)
- COMPACFLT(COMmander, PACific FLeeT (formerly CINCPACFLT))
- COMPACT(COMmittee to Preserve American Color Television)
- COMPARE(Citizens Opposing the Megamall and Proposed Access Road Extension)
- COMPAS(Curriculum-Oriented Mathematics Placement for Academic Success)
- COMPASS(Community Organisations Management Planning And Support Services)