CLS may refer to:
Academic fields
- Critical legal studies, school of legal philosophy
- Constrained least square statistical estimator
- CLs method to set bounds on particle physics model parameters
Education
- California Labor School, San Francisco, US 1942–57
- City of London School, UK
- Covington Latin School, Kentucky, US
- Crystal Lake South High School, Illinois, US
- Chicago Law School at The University of Chicago, US
- Columbia Law School at Columbia University, US
- Cornell Law School at Cornell University, US
- Coalition of Latino and Latina Scholars at Teachers College, Columbia University, US
- Critical Language Scholarship Program of the US State Department
Societies and associations
- Caribbean Labour Solidarity, based in London, UK
- Chicago Linguistic Society
- Christian Legal Society
- Communist League of Struggle, US, 1931-1937
Software and technology
- Cable landing station, where a submarine cable comes ashore
- Common Language Specification, Microsoft
- CLS (command) to clear computer screen in several environments
- CLS (BASIC command)
- CLS (DOS command)
- CLS (OS/2 command)
- CLS (Windows command)
- CLS (CONFIG.SYS directive), in DR-DOS
- Creative Lighting System, in Nikon speedlights
Medical and science
- Computational Science, an academical research discipline
- Canadian Light Source, a synchrotron light source
- Clinical laboratory science, another name for Medical Technology or Medical Laboratory Science
- Combat lifesaver, US non-medical military role
Music
- City of London Sinfonia
- CLS Music, a record label
- Cali Life Style, a Hip Hop act
Transportation and vehicles
- Capsule launch system for space capsules
- Mercedes-Benz CLS-Class, automobile models
Business and finance
- CLS Group, US financial institution
- Celestica, New York Stock Exchange symbol
- CLS Communication, translation services
- Core Labor Standards, ILO