MEC
- Eloy Alfaro International Airport
- MEC (basketball)
- MEC (media agency)
- MEC Canada
- Madureira Esporte Clube
- Maine Central Railroad
- Manufacturing Engineering Centre
- Marginal efficiency of capital
- Master of Economics
- Measured environmental concentration
- Mec, Poland
- Media Expansion Card
- Mediterranean Exploration Company
- Member of the Executive Council
- Meols Cop railway station
- Methodist Episcopal Church
- Metropolitan Evangelistic Church
- Microbial electrolysis cell
- Midland Empire Conference
- Ministry of Education (Brazil)
- Ministry of Education and Culture (Uruguay)
- Model Engineering College
- Mongolia Energy Corporation
- Morgan Electro Ceramics
- Motor Enthusiasts Club
- Mountain East Conference
- Mountain Equipment Co-op
- Movement for Economic Change
- Mucoepidermoid carcinoma
- Multi-access edge computing
- Munitions and explosives of concern
- Myanmar Economic Corporation
- Mymensingh Engineering College