CASL may refer to:
- Cache Accelerated Sequential Layout
- Canadian Association for School Libraries
- Capital Area Soccer League
- Center for Advanced Study of Language
- Commercial Aircraft Sales and Leasing
- Common Algebraic Specification Language
- Compact Application Solution Language
- China Aircraft Services Limited
- Complex and adaptive systems laboratory
- Fighting Internet and Wireless Spam Act, often referred to as "Canada's Anti-Spam Law" or "CASL"