MGA can refer to:

Transport

• MGA, IATA code for Augusto C. Sandino International Airport (Managua International Airport) in Managua, Nicaragua
• Monongahela Railway, a former coal-hauling short line railroad in the United States
• The MG MGA, a popular British sports car manufactured between 1955 and 1962 by MG

Business and finance

• Malagasy ariary, currency of Madagascar by ISO 4217 currency code
• Managing general agent, a type of insurance agent
• Mutual Gains Approach, a process model for negotiating while protecting relationships and reputation

Biology and health care

• 3-Methylglutaconic aciduria, a metabolic disorder
• Mga (protein), a DNA-binding protein found in Streptococcus pyogenes (group A Streptococcus)
• Mga, max dimerization protein, a protein in humans encoded by the MGA gene
• Megestrol acetate or melengestrol acetate, progestin medications

Geography

• Map Grid of Australia, a mapping system based on the Universal Transverse Mercator coordinate system
• Mga (river) in Leningrad Oblast, Russia
• Mga, an urban-type settlement in Leningrad Oblast, Russia

Information technology

• Matrox, producer of video card components
• Monochrome Graphics Adapter, either related to or synonymous with the Hercules Graphics Card
• Multigenerational architecture, a method of database transactions handling related to multiversion concurrency control

Education

• Master of Governmental Administration, a degree program offered by the Fels Institute of Government
• Master of Global Affairs, a degree program offered by the Munk School of Global Affairs and Public Policy at the University of Toronto

Arts

• Monash Gallery of Art, Melbourne, Australia.

Organizations

• Malta Gaming Authority, Malta's gaming control board
• Midwestern Governors Association, a nonprofit organization of the 12 American Midwest states' governors
• A subsidiary of Mitsubishi

Entertainment

• Marriott's Great America, earlier name of Great America, former name of amusement parks
• Metal Gear Acid, a PlayStation Portable video game by Konami
• Metal Gear Arcade, a reworked arcade version of the Metal Gear Online video game by Konami
• MGA Entertainment, a toy production company
• Mint Green Army, the football team of St Anne's College, Oxford

Linguistics

• In the Filipino language, "mga" (pronounced as [mɐˈŋa]) is used as a prefix to pluralize nouns.