XL or xl may stand for:
- 40 (number) in Roman numerals
In business:
- Extra large, a clothing size
- XL Airways France, a French airline
- XL Airways Germany, a German charter airline
- XL Axiata, an Indonesian mobile phone network operator
- XL Center, a civic center in Hartford, Connecticut, United States
- XL Group, a financial services company headquartered in Ireland with executive offices in Bermuda
- XL Recordings, a British independent record label
- XL Leisure Group, a major United Kingdom tour operator, which ceased operations in 2008
- XL Airways UK, a defunct British airline which was part of XL Leisure Group
- LAN Ecuador's IATA code
- Excess-of-loss reinsurance, a particular non-proportional type of reinsurance contact
In science and technology:
- XL, inductive reactance, a property of an inductor
In computers:
- the XL series computers in the Atari 8-bit family (including the 600XL, 800XL and 1200XL)
- XL (programming language), a computer programming language designed to support concept programming
- Weather Star XL (also known as just XL), a computer used by The Weather Channel for local forecasts
In entertainment:
- XL (eXplicit Language), a content descriptor used by XM Satellite Radio
- XL, a character in Buzz Lightyear of Star Command
Other:
- North Texas Intermediate Sanctions Facility (TDCJ shorthand is "XL")