OSL

OSL may refer to:

Computing:
 * Open Software License, an open-source software license

Technology:
 * Open Shading Language, a shading language
 * Optically stimulated luminescence, a method of measuring doses from ionizing radiation, which is often used in mineral dating

Other:
 * Ongamenet Starleague, a tournament for professional StarCraft players in South Korea
 * Ontario Soccer League, a semi-pro soccer league in Ontario, Canada
 * Orchestra of St. Luke's, chamber orchestra in Manhattan, New York City
 * Order of Saint Luke, a Methodist religious order
 * Oregon Short Line Railroad, a former railroad in the U.S. states of Wyoming, Idaho, Utah, Montana and Oregon
 * Oslo Airport, Gardermoen, IATA airport code
 * Outside Lands, a music and arts festival that takes place annually in San Francsico's Golden Gate Park
 * Oud-Strijders Legioen, a Dutch right-wing organization (1952–2010)
 * Sosoliso Airlines, ICAO airline designator