USL may refer to:
- Arts and entertainment
- Underground Sound of Lisbon, a Portuguese dance music project
- Urban Strawberry Lunch, a Band from Liverpool
- USL, a music Club in Switzerland
- Computing
- Universal Systems Language, a language for system engineering and software development
- Unix System Laboratories, a defunct American software company
- Education
- University of Louisiana at Lafayette, formerly known as "University of Southwestern Louisiana" (USL), a university in the United States
- University of Saint Louis Tuguegarao, a private university in the Philippines.
- University of Sierra Leone, the public university system in Sierra Leone
- Sports
- Ultimate Soccer League, Semi-professional indoor soccer league
- United Soccer League, defunct U.S. soccer league active 1983–1984
- United Soccer Leagues, the parent organization for the men's lower division leagues of US Soccer, as well as a women's league and a youth league
- Transportation
- United States Lines, a defunct American shipping company
- Politics
- Social Liberal Union, a political alliance in Romania