In

IN, In or in may refer to:

Places

 * India (country code IN)
 * Indiana, United States (postal code IN)
 * Ingolstadt, Germany (license plate code IN)
 * In, Russia, a town in the Jewish Autonomous Oblast

Businesses and organizations

 * Independent Network, a UK-based political association
 * Indiana Northeastern Railroad (Association of American Railroads reporting mark)
 * Indian Navy, a part of the India military
 * Infantry, the branch of a military force that fights on foot
 * IN Groupe, the producer of French official documents
 * MAT Macedonian Airlines (IATA designator IN)
 * Nam Air (IATA designator IN)

Science and technology

 * .in, the internet top-level domain of India
 * Inch (in), a unit of length
 * Indium, symbol In, a chemical element
 * Intelligent Network, a telecommunication network standard
 * Intra-nasal (insufflation), a method of administrating some medications and vaccines
 * Integrase, a retroviral enzyme

Other uses

 * In (album), by the Outsiders, 1967
 * In (Korean name), a family name and an element in given names
 * "In", an episode of Minder
 * Imperishable Night, the eighth official game in the Japanese Touhou series
 * Indonesian language (former ISO 639-1 language code; "id" used since November 3, 1989)
 * In Nomine, a title given to any of numerous short pieces of English polyphonic instrumental or vocal music during the 16th and 17th centuries