TSO

TSO may refer to:

Science and technology

 * Technical Standard Order, a minimum performance standard issued by the FAA for certain items used on civil aircraft
 * Transmission system operator, an entity involved in electric power transmission or transmission of natural gas
 * Trichuris suis, a species of whipworm, a parasite of pigs

Computing

 * TCP segmentation offloading, a technique for increasing outbound throughput of high-bandwidth network connections
 * Time Sharing Option, an interactive command line interpreter for IBM mainframe operating systems OS/360, SVS, MVS, OS/390 and z/OS
 * Total store order, in microprocessor memory ordering

Music

 * Taipei Symphony Orchestra
 * Tasmanian Symphony Orchestra
 * Tehran Symphony Orchestra
 * The Summer Obsession
 * Tokyo Symphony Orchestra
 * Toledo Symphony Orchestra
 * Toronto Symphony Orchestra
 * Trans-Siberian Orchestra
 * Tucson Symphony Orchestra

Transportation

 * Transaero Airlines (ICAO airline designator code), a former Russian airline
 * Tresco Heliport (IATA airport code), a former heliport in the Scilly islands
 * Tourist Standard Open, a type of British Railways loco-hauled coach
 * Trailer Standard Open, a type of British Railways coach
 * Marcos TSO, a sports car manufactured by Marcos Engineering Ltd
 * Transportation security officer, a federal employee of the Transportation Security Administration, a division of the U. S. Department of Homeland Security

Other uses

 * Threefold social order, a sociological theory involving the relationship of economy, polity and culture
 * The Sims Online, a massively multiplayer game
 * The Stationery Office, a British publisher
 * Total shares outstanding, the stock held by investors, including restricted shares, as well as those held by the public; see shares outstanding