EIR

EIR may refer to:
 * Effective interest rate, a banking term
 * Entrepreneur In Residence or Executive In Residence, a term in venture capital and business education
 * Environmental Information Regulations 2004, a UK Statutory Instrument
 * Equipment Identity Register, in a Network Switching Subsystem
 * Extended information rate, burstable bandwidth in a Frame Relay network
 * Establishment Inspection Report, the result of an investigation by the US FDA.
 * Environmental Impact Report, see Environmental impact assessment
 * Executive Intelligence Review, the flagship publication of the LaRouche movement
 * Kodak Ektachrome Professional Infrared/EIR film, a type of Color Infrared film
 * Ethniko Idryma Radiofonias, the National Radio Foundation of Greece
 * East Indian Railway Company, introduced railways to eastern and northern India, later known as East Indian Railway (EIR)
 * East Indian rosewood, one of the common names for Dalbergia latifolia and its hardwood

Eir may refer to
 * Eir, a goddess in Norse mythology
 * Eir (telecommunications), a major provider of telecommunications in Ireland
 * Eir, a Spivak pronoun
 * Eir, a character from the mobile video game Fire Emblem Heroes
 * Eir Aoi, Japanese singer