GLA may refer to:
Institutions:
- Gangmasters Licensing Authority, a UK regulatory body for gangmasters
- General Lighthouse Authority, the generic term for national lighthouse authorities
- Greater London Authority, a body which administers Greater London
In science and technology:
- GaLactosidase Alpha, an enzyme
- gamma-Linolenic acid, an omega-6 fatty acid
- Gamma-carboxyglutamic acid, an amino acid important in vitamin K-dependent proteins and found in Gla domains.
Other uses:
- Glasgow International Airport (IATA airport code GLA)
- Global Liberation Army, a fictional group in the video game Command and Conquer: Generals
- Grand Larceny Auto, a term for motor vehicle theft used in some police jurisdictions
- Great Lakes Airlines (ICAO airline code GLA)
- Great Lakes Avengers, a fictional comic hero group
- Gross leasable area, in retail development, the amount of floor space available to be rented
- Global Leadership Adventures, international high school study abroad program