MGA can be an abbreviation of:
- The IATA code for Managua International Airport located in Managua, Nicaragua; also known as the Augusto C. Sandino International Airport
- Master of Governmental Administration, a degree program offered by the Fels Institute of Government
- Malagasy ariary, the ISO 4217 code for the currency of Madagascar
- Marriott's Great America (disambiguation), former name of amusement parks
- Matrox
- Metal Gear Acid, a PlayStation Portable video game by Konami
- Metal Gear Arcade, an arcade video game by Konami
- Midwestern Governors Association, a nonprofit organization of the 12 American Midwest states' governors.
- Monochrome Graphics Adapter
- Monongahela Railway
- Mutual Gains Approach
- MGA Entertainment, a private toy company, who manufacture the world famous Bratz dolls.
- Managing general agent
- Mint Green Army, the football team of St Anne's College, University of Oxford
- The subsidiary of Mitsubishi
- MG MGA, a popular British sports car manufactured between 1955 and 1962 by MG
- Mga (protein), a DNA-binding protein found in S. pyrogenes