TLS may refer to:

Computing

• Transport Layer Security, a cryptographic protocol for secure computer network communication

• Thread level speculation, an optimisation on multiprocessor CPUs

• Thread-local storage, a mechanism for allocating variables in computer science

• Transparent LAN Service, a transparent data link connecting remote Ethernet networks

Media

• Theaterlexikon der Schweiz, an encyclopedia about theatre in Switzerland

• The Times Literary Supplement, a British fortnightly literary review

• Town Life Stuff, one of The Sims 3 Stuff packs

Organisations

• Telstra (ASX code), an Australian telecommunications and media company

• Trans Link Systems B.V., a company delivering the OV-chipkaart system to public-transport operators in the Netherlands.

• Transmitter Location Systems, a US satellite radio interference geolocation company

Education

• The Lindsey School, a secondary school in Cleethorpes, North East Lincolnshire, England

• Tallinn Law School, in Estonia

• Torrey Life Science, a biology organization of the University of Connecticut, US

• Trinity Law School, in Santa Ana, California, US

• Trinity Lutheran School (disambiguation), several schools in the US

• Tulane University Law School, in New Orleans, Louisiana, US

Science, medicine and technology

• Thüringer Landessternwarte Tautenburg, the Karl Schwarzschild Observatory, in Tautenburg, Thuringia, Germany

• Terrestrial laser scanning, a 3D laser scanning method

• Total least squares, a statistical analysis

• Translesion synthesis, a form of DNA repair

• Transponder landing system, an airplane landing system

• Tumor lysis syndrome, a group of metabolic complications that can occur after treatment of cancer

• Tunable laser spectrometer, an instrument in the Mars rover suite Sample Analysis at Mars

• Two-level system, a quantum system

Transport

• Thorpe-le-Soken railway station, Tendring, England (National Rail station code)

• Toulouse–Blagnac Airport (IATA code)

Other uses

• East Timor (IOC code)