CSL as an abbreviation may stand for:

Places

• Coordinated Science Laboratory, at the University of Illinois
• Liège Space Center (Centre spatial de Liège), at the University of Liege in Belgium
• Central Science Laboratory, a former UK DEFRA laboratory services agency

Languages

• Croatian Sign Language, a sign language for the deaf in Croatia
• Chinese Sign Language, a sign language for the deaf in China, Malaysia, and Taiwan
• Clay Sanskrit Library, a series of books in Sanskrit with English translations
• Context-sensitive language, a class of formal languages in computational linguistics

Sciences

• Crosshole sonic logging, method for testing a constructed material
• Calcium stearoyl-2-lactylate, a food additive used as an emulsifier
• Continuous spontaneous localization, a dynamical reduction theory in quantum mechanics
• Hartmann's solution, compound sodium lactate, used in intravenous transfusions

Military

• Cooperative Security Location, a US military facility
• CSL, the designation code for Royal Australian Navy Wattle-class crane stores lighters

Computing

• Citation Style Language, an open XML-based standard to format citations and bibliographies
• Current-steering logic, an alternative name for emitter-coupled logic in electronics
• Context-sensitive language, a language generated from a context-sensitive grammar

Companies

• CSL Mobile, subsidiary of Hong Kong Telecom
• CSL Limited, an Australian biotechnology company, formerly Commonwealth Serum Laboratories
• CSL Behring, a daughter company of CSL Limited
• Canada Steamship Lines, a Canadian shipping company
• CSL Sofas, a furniture chain in the United Kingdom
• Cochin Shipyard Limited, a shipbuilding company in Kerala, India

Sports

• CAL Spora Luxembourg, amateur athletics club in Luxembourg
• Canadian Soccer League, a soccer league in Canada since 2006
• Canadian Soccer League (1987–1992), a soccer league in Canada
• Chinese Super League, the premier league of association football in China
• Cosmopolitan Soccer League, a soccer league in United States

Politics

• Canadian Socialist League, a political party active from 1898 to 1904
• Czechoslovak People's Party (Československá strana lidová, ČSL), a political party

Others

• Centers for Spiritual Living, a religious denomination
• Certain models of BMW car, designated BMW CSL
• Charter seat license, name used by a few sports teams for a personal seat license