NS as an abbreviation can mean:
Arts and entertainment Gaming Natural Selection (video game), a mod for the game Half-Life NetStorm: Islands At War, a real-time strategy game published in 1997 by Activision Nintendo Switch, a hybrid video game console and handheld. NationStates, a web-based simulation game
Literature New Spring (known to fans as "NS"), a 1999 anthology edited by Robert Silverberg and derivative 2004 novella by Robert Jordan NS-series robots from the book I, Robot
Companies National Semiconductor (also known as "Natsemi"), an American integrated circuit design and manufacturing company Nederlandse Spoorwegen, the main public transport railway company in the Netherlands Norfolk Southern Railway, a major Class I railroad in the United States, owned by the Norfolk Southern Corporation Norfolk Southern Railway (1942–1982), the final name of a railroad running in Virginia and North Carolina before its acquisition by the Southern Railway in 1974
Government and politics Nasjonal Samling, a 1930s Norwegian national socialist political party National Security Department (noted as NS), a law enforcement agency in Hong Kong National service, a name for the conscription system of some militaries National Socialism or Nazism, the ideology held by, among other political parties, the National Socialist German Workers Party New Serbia (political party) (Nova Srbija), a political party in Serbia People's Party (Serbia, 2017) (Narodna stranka), a political party in Serbia New Slovenia (also known as Nova Slovenija - Krscanski Ljudska Stranka), a right-of-centre political party in Slovenia People's Party (Montenegro) (Narodna Stranka), a political party in the Republic of Montenegro National Alliance (Lithuania) (Nacionalinis susivienijimas), a political party in Lithuania
Places Negeri Sembilan, one of the fourteen states in Malaysia Novi Sad, a city in Serbia (license plate code) Nova Scotia, as the official Canadian postal abbreviation for the province
Science and technology Biology and medicine Nervous system, the system of neurons that coordinates the actions of an organism Normal saline, a solution of sodium chloride used in intravenous drips
Computing Name server, a computer server that implements a name service protocol NS record, a DNS record type Namespace, an abstract container used in computing Neighbor Solicitation, part of IPv6's Neighbor Discovery Protocol NeXTSTEP, an object-oriented, multitasking operating system by NeXT, as well as a prefix for certain system-provided classes in the operating system, such as "NSString" ns (simulator) (or "ns-2"), an open source network simulator
Mathematics ns (elliptic function), one of Jacobi's elliptic functions NS, the Néron–Severi group
Other uses in science and technology Nanosecond (abbreviated "ns"), a measure of time Nanostructure Neutron star, a star formed from the collapsed remnant of a massive star New Shepard 3 (NS3), a reusable launch vehicle from Blue Origin, being tested in 2017-18 Newton second, the SI derived unit for momentum Not significant, when differences between categories are smaller than the amount of error/noise in the data, see Statistical significance Nuclear Ship (NS), a ship prefix for civilian ship names Norsk Standard, Norwegian Standard, Standards defined by Standard Norge
Other uses National school (Ireland), a type of school New Style (as "N.S." in opposition to Old Style as "O.S."), indicating either a date in the Julian Calendar with the start of year adjusted to 1 January, or a date in the Gregorian calendar