LDA may refer to:
Aviation Localizer type directional aid, a landing procedure Landing distance available, a runway length
Law Legal document assistant, an independent paralegal role Lobbying Disclosure Act of 1995, United States Legal drinking age, a minimum age of alcohol consumption
Music LDA (singer) (born 2003) Little Dark Age, a 2018 MGMT album
Organizations Lahore Development Authority, agency in Lahore, Pakistan Left Democratic Alliance, left-wing political alliance in Bangladesh Liga Deportiva Alajuelense, a Costa Rican football club London Democratic Association, 19th century organisation in England London Development Agency, regional development agency for the London region in England Lord's Day Alliance, an ecumenical Christian first-day Sabbatarian organization
Science and technology Laser Doppler anemometry, to measure velocity Latent Dirichlet allocation, in natural language processing Left-displaced abomasum, a condition of ruminants Linear diode array, in X-ray imaging Linear discriminant analysis, in statistics Lithium diisopropylamide, a chemical base Local delivery agent, in e-mail Local-density approximation, in quantum mechanics Low density amorphous ice, a solid phase of water Lobate debris apron, a Martian landform Low dose allergens, a variant of enzyme potentiated desensitization