| Acronym | Definition |
|---|
| MEC | Mountain Equipment Co-Op |
| MEC | Ministério da Educação (Ministry of Education) |
| MEC | Ministerio de Educación y Ciencia (Spain: Ministry for Education and Science) |
| MEC | Model Energy Code |
| MEC | Ministério da Educação e Cultura (Brazilian Ministry Of Education) |
| MEC | Ministerio de Educación Y Cultura (Spanish) |
| MEC | Member of the Executive Council |
| MEC | Munitions and Explosives of Concern |
| MEC | Modified Endowment Contract |
| MEC | Ministry of Education and Culture |
| MEC | Magnolia Electric Co. (band) |
| MEC | Mitsubishi Estate Co Ltd |
| MEC | Middle-Eastern Coalition |
| MEC | Media-Edge:CIA (US advertising agency) |
| MEC | Medical Education Collaborative |
| MEC | MidAmerican Energy Company |
| MEC | Michigan Environmental Council (Lansing, MI) |
| MEC | Manufacturing Engineering Centre |
| MEC | Magna Entertainment Corporation |
| MEC | Microcomputers in Education Conference |
| MEC | Marginal External Cost |
| MEC | Management Education Center |
| MEC | Metropolitan Educational Council (Ohio) |
| MEC | Mercato Comune Europeo (Italian: European Economic Community |
| MEC | Microsoft Exchange Conference |
| MEC | Main Engine Control |
| MEC | Master Events Controller |
| MEC | Medial Entorhinal Cortex (mammalian brain area) |
| MEC | Massachusetts Electric Company |
| MEC | Mechanical Equipment Center (McMurdo Station, Antarctica - USAP) |
| MEC | Minimum Explosive Concentration |
| MEC | Main Engine Controller |
| MEC | Meson Exchange Current |
| MEC | Maine Central Railroad Company |
| MEC | Movimento Ecclesiale Carmelitano (Italian) |
| MEC | Medium Endurance Cutter (US Coast Guard) |
| MEC | Mechatronics Education Center (Columbus, NE) |
| MEC | Marin Employment Connection (San Rafael, CA) |
| MEC | Microsoft Enterprise Cube |
| MEC | Medical Examiners Commission |
| MEC | Mission Essential Competencies (US DoD) |
| MEC | Mobile Equipment Console |
| MEC | Missouri Employer Committee |
| MEC | Mohave Electric Cooperative, Inc. |
| MEC | Marine Evacuation Chute |
| MEC | Marine Energy Challenge |
| MEC | Modular Equipment Controller |
| MEC | Month End Closing |
| MEC | Marshalls Energy Company, Inc. (Marshall Islands) |
| MEC | Military Essentiality Code |
| MEC | Maritime Electric Company, Limited |
| MEC | Main Entry Catalogue (Canada) |
| MEC | Macro Expansion Counter |
| MEC | Multi Regional Ethics Committee (New Zealand Association of Clinical Research) |
| MEC | Minimal Effective Plasma Concentration |
| MEC | Maintenance/Metrology Engineering Center |
| MEC | Master Executive Counsel |
| MEC | Miniature Embedded Converter |
| MEC | Marquess Educational Consultants, Ltd. (London, England, UK) |
| MEC | Main Element Contractor |
| MEC | Main Engine Cylinder |
| MEC | Main/Master Evaluation Center |
| MEC | Message Error Correction |
| MEC | Modulated Estimate Correction |
| MEC | Mutual Execution of Contract (real estate) |
| MEC | Mechanical End Connector (pipeline connections) |
| MEC | Microgravity Environment Compatibility |
| MEC | Minimum Essential Communications |
| MEC | Misión Educativa Cristiana (Guatemala) |
| MEC | Missile Event Conference |
| MEC | Mercury Encrypted Communicator |
| MEC | Maintenance Engineer Call |
| MEC | Matra Enthusiasts Club (automobile club; UK) |
| MEC | Mobile Embedded Computer |
| MEC | Model for Environmental Costs |
| MEC | Middle English Compendium |
| MEC | Master Events Calendar (various organizations) |
| MEC | Medical Education Centre (various locations) |
| MEC | Medical Education Committee (various schools) |
| MEC | Midlands Energy Consortium (UK) |