ISL

Isl (or isl) is a common abbreviation for "island" or "islands".

ISL may also refer to:

Education and research

Illinois Security Lab, a research laboratory at the University of Illinois at Urbana-Champaign
Independent School League (disambiguation), independent high school athletic conferences in the United States
Institute of State and Law, a Russian legal think tank affiliated with the Russian Academy of Sciences
International School of Louisiana, a charter school system in the United States
International School of Lusaka, an international school in Zambia
International School of Luxembourg, a privately owned non-profit school in Luxembourg
International School of Lyon, an international school in France

Icelandic language, the national language of Iceland
Icelandic Sign Language, the sign language of Iceland
Indian Sign Language also known as sign language of the deaf community in India
International Sign Language, any of several international auxiliary languages
Irish Sign Language, the sign language of Ireland
Israeli Sign Language, the most commonly used sign language within Israel's deaf community
Italian Sign Language, sign language used for Italian deaf people

Independent School League (Illinois), a group of nine Chicago-area preparatory schools
Independent School League (New England), a group of 16 New England preparatory schools
Independent School League (Washington, D.C. area), a group of 17 Washington, D.C. preparatory schools
Interscholastic League of Honolulu, a group of Hawaiian private schools
Indian Super League, a professional football-club league based in India
Ice Hockey Superleague, a British-based ice hockey league that existed between 1996 and 2003
Indonesia Super League, the top-tier competition for football clubs in Indonesia
International Soccer League, a U.S. based soccer league which was formed in 1960 and collapsed in 1965
International Sport and Leisure, a bankrupt Swiss sports marketing company that was closely affiliated with FIFA and the IOC
Iranian Super League (disambiguation), the Iranian professional basketball, futsal or volleyball leagues
Island Soccer League, a professional six-a-side association football league based in Bermuda
International Swimming League, a professional swimming league with ten teams and nine rounds in different cities all over the world

Island line (MTR), one of the rapid transit railway lines in Hong Kong
Isleworth railway station (National Rail station code ISL), Hounslow, London, England, UK
Atatürk Airport (IATA airport code ISL), a former major international airport serving Istanbul, Turkey now serves cargo flights
Iowa and St. Louis Railway (I&SL), U.S.

Independent Socialist League, a defunct Trotskyist group in the United States (originally called the "Workers Party")
International Socialist League (South Africa), a former syndicalist group
International Socialist Left (Germany) ({{Langx|de|Internationale Sozialistische Linke|links=no}}), a Trotskyist group in Germany

Iceland, a Nordic European island country
In situ leach, a mining technique
Independent state legislature theory, U.S. Constitution reading
Integer set library (isl), a programming library for manipulating integer sets
Inter-Switch Link (disambiguation), a specially configured connection between network equipment
Cisco Inter-Switch Link, a proprietary Cisco VLAN trunking protocol
Intercon Security, a security firm
International Service Learning, a humanitarian NGO that offers volunteers practical experience in medical, education, and community enrichment programs
Irish Shipping Limited, an Irish state-owned deepsea shipping company formed during World War II
i. s. L., "in the sense of Lyapunov" (in mathematical contexts), a reference to Lyapunov stability
Postal code for Senglea, Malta ({{Langx|mt|Isla|links=no}})