NN, Nn, or nn may refer to:
Arts and media NN (film), a 2014 Peruvian film Nintendo Network, a discontinued Nintendo service The Abominable Snowmen, a 1967 Doctor Who serial (production code NN)
Businesses and organizations Nationale-Nederlanden, a Dutch insurance company commonly referred to as NN Netroots Nation, a political convention for American progressive activists Nevada Northern Railway (reporting mark NN) Norilsk Nickel, а metallurgical and mining company VIM Airlines (IATA airline designator NN) Nigerian Navy, part of the armed forces of Nigeria New Hope (Polish: ), a Polish far right party
Language , a digraph; see Ñ, a letter in Spanish, originally derived from the written "nn" Nynorsk, a Norwegian written language (ISO 639 alpha-1 code "nn"), as distinguished from Bokmål (code "no")
People Camillo Almici, 18th-century Italian priest known by the pseudonym N.N. Nick Nurse, head coach of the NBA's Toronto Raptors Sergei Prokopovich, Russian economist known by the pseudonym N.N.
Places NN postcode area, UK, for areas of Northamptonshire, England Newport News, a city in Virginia, United States Nizhniy Novgorod, a Russian city
Science and technology Nearest neighbor (disambiguation), with several related uses in mathematics Net neutrality, the principle that Internet service providers should treat all data the same Neural network, a group of interconnected nerve cells or a machine-learning model inspired by one Neutronium, a hypothetical element with chemical symbol nn Normalnull, a German height reference system preceding Normalhöhennull (NHN)
Other uses Double net lease, a type of lease used for commercial real estate Nomen nescio (Latin for "no name"), a person whose name is unknown