SLA may refer to:
in geography,
- Martín Miguel de Güemes International Airport, Salta Province, Argentina (by IATA code)
- South Los Angeles
- State Line Avenue, in Texarkana, United States
in science and engineering,
- Sealed lead-acid, a type of lead-acid battery
- Second-language acquisition, the process by which people learn additional languages
- Short long arms suspension, a wheel suspension type for vehicles with wishbones of unequal length
- Specific leaf area, a botanical term describing a property of a leaf on a plant, often used as a measure of leaf "thickness"
- Stereolithography apparatus, a type of rapid prototyping machine
in organizations,
- Saint Lawrence Academy, a college preparatory school located in Santa Clara, California
- School Library Association, an association for school librarians
- South Lebanon Army, an Israeli-backed militia during the Lebanese Civil War
- Special Libraries Association, an association for professional librarians working in specialized libraries
- Sri Lanka Army, the oldest and largest of Sri Lanka's armed services
- State Liquor Authority, New York State organization that enforces liquor laws
- Sudan Liberation Movement/Army, a rebel group in the Sudanese region Darfur
- Symbionese Liberation Army,1970's Radical group and kidnappers of Patricia Campbell Hearst
- Sociedat de Lingüistica Aragonesa, Aragonese language society
- Singapore Land Authority, a statutory board under the Ministry of Law of Singapore
in other uses,
- Service-level agreement, a contractual agreement on the level of service to be provided by a service provider to a customer, commonly used in computer-related services
- Single life annuity, a form of recurring payment
- Shared line appearance, a technique used in telephony
- SLA Industries, a role-playing game written by Nightfall Games
- Savings and loan association, savings banks in the United States of America
- Slow left arm, a bowling style in cricket
- Software license agreement, a contract placing restrictions on the use of software
- Source level adjuster, a feature present on some car audio equipment
- .sla, a file extension used in the open-source software Scribus
- The Softwood Lumber Agreement, part of the United States–Canada trade dispute