TN

Tn or TN may refer to:

Businesses and organizations

 * Air Tahiti Nui (IATA airline designation "TN" since 1998), a French Polynesian airline
 * Texas and Northern Railway, an American railway (reporting mark "TN")
 * Todo Noticias, an Argentine cable news network
 * Trans Australia Airlines (IATA airline designation "TN" until 1994), a defunct Australian airline
 * Transports en commun de Neuchâtel et environs, a public transport operator in Neuchâtel, Switzerland

Places

 * Tamil Nadu, a state in southern India (ISO abbreviation "IN-TN")
 * Tennessee, US (postal abbreviation "TN")
 * Tonbridge, a region in England (postcode "TN")
 * Tunisia (ISO 3166-1 country code "TN")
 * Trentino, a province in Italy (ISO abbreviation "IT-TN")
 * North Tipperary, a former county of Ireland (car plate code "TN")

Science and technology

 * .tn, the country code top level domain (ccTLD) for Tunisia
 * TN network, a type of earthing system for protection in electricity network
 * Neel Temperature, the temperature at which an antiferromagnetic material becomes paramagnetic (represented as TN)
 * Tetraodon, a genus of pufferfish
 * Trigeminal neuralgia, a neuropathic disorder
 * Transposon (when immediately followed by a number), a DNA sequence that can change positions
 * Twisted nematic field effect, the technology that made LCD displays practical
 * Thoron, symbol Tn, a sometimes used name for the nuclide radon-220

Other uses

 * TN status ("Treaty national", or "Trade NAFTA"), an immigration status of a Canadian or Mexican citizen working in the USA under the NAFTA agreement
 * Telephone number, in the telecommunications industry
 * Tom Next (or Tomorrow Next), a financial trade which starts tomorrow and settles in the next trading day
 * Trillion ("TN" or "tn"), a number equal to 1012 (short scale) or 1018 (long scale)
 * Tswana language (ISO 639-1 language code)
 * Translators Note ("TN" or "t/n")
 * Turbonave, an Italian ship prefix, indicating that the ship was propelled by a turbine engine.