Ir or ir may refer to:

  • the abbreviation (Ir.) for the title of IngĂ©nieur (Engineer), a person practicing the profession of engineering
  • Iridium (chemical symbol Ir), the 77th element
  • .ir, the Internet country code top-level domain for Iran

IR may refer to:

  • Iran, which has the country code IR
  • International Relations, in political science, the study of foreign affairs of and relations among states
  • Investor relations, a management responsibility in which companies disclose information for regulatory compliance and for bond/share-holders to make investment judgments
  • Injured reserve list, a reserve list for professional teams to use if a player is injured and unable to play for an extended time
  • International rules football a hybrid code of football
  • Independent-Republican Party of Minnesota, currently known as Republican Party of Minnesota
  • Instrument rating, the qualifications a pilot must have in order to fly under Instrument Flight Rules (IFR)
  • Impulse response, is a function of a dynamic system of its output when presented with a brief input signal
  • Imaginary Realities, a MUD community online magazine
  • International Rescue (disambiguation)
  • Interracial (disambiguation)
  • In mathematics, the set of real numbers is sometimes written on computers as "IR", the I standing as the R's double-bar.

Read more about IR:  Organizations, Science and Medicine, Finance, Computing, Popular Culture