Sensei's Library (commonly referred to as SL among Go-players) is an Internet website and wiki, dedicated to articles about, and discussion of, the game of Go. Sensei's Library was started in September 2000, by the Go players Morten Pahle and Arno Hollosi. Hollosi is also known for designing version 4 of Anders Kierulf's popular SGF file format and for his work with the Austrian Citizen Card project.
Sensei's Library is used for a number of purposes, and contains over 20,000 pages  on a wide range of topics, such as the culture and history of Go, Go theory, strategy, and community information. It is highly regarded in the Go community. One reviewer noted that as "a collaborative resource written by contributors, Sensei's Library may be the most extensive go resource on the web. Articles cover a variety of topics, including possibly the best discussion of endgame theory published anywhere." Among its contributors are some published Go authors, such as Charles Matthews and John Fairbairn.
- Morten Pahle. "SL History". Retrieved 2008-12-11.
- "SGF File Format FF(4) Page". Retrieved 2007-03-28.
- "Arno Hollosi, "Austria's Citizen Card and Beyond," Int. Conf. on Electronic Identity and Interoperability, 16th April 2004, Rome, Italy" (PDF). Retrieved 2008-05-04.
- "Sensei's Library: Front Page". Retrieved 2010-06-01.
- Philip Waldron. "GO REVIEW: Top 10 Go Websites". Retrieved 2008-12-11.
- Terri Schurter. "American Go Association e-journal October 2001". Retrieved 2011-05-18.
- "St Louis Go Association web site". Retrieved 2011-05-18.
- "GoGoD recommended links". Retrieved 2011-05-18.
- "MSO article on John Fairbairn". Retrieved 2007-03-28.
- "Charles Matthews Player Page". Retrieved 2007-03-28.