Ein

Ein or EIN may refer to:

Science and technology

 * Ein function, in mathematics
 * Endometrial intraepithelial neoplasia, a lesion of the uterine lining
 * Equivalent input noise, of a microphone
 * European Informatics Network, a 1970s computer network

Fictional characters

 * Ein, a character in the anime series Cowboy Bebop
 * Ein, a character in the video game series Dead or Alive
 * Ein, the protagonist of the Game Boy Advance game Riviera: The Promised Land

Other uses

 * Aer Lingus (ICAO code), the flag carrier airline of Ireland
 * Eindhoven Airport (IATA code), in the Netherlands
 * Employer Identification Number, assigned by the US Internal Revenue Service
 * EPODE International Network, a Belgian obesity organization