AAR or Aar may refer to:
Aviation AAR Corporation, an American aviation engineering company Air-to-air refueling, the process of transferring aviation fuel from one military aircraft to another during flight Aarhus Airport in Mid Jutland Region, Denmark (IATA airport code AAR) Asiana Airlines of South Korea (ICAO airline code AAR)
Places Aar, a river in Switzerland, tributary of the Rhine Aar (Lahn), a tributary of Lahn river in Germany, descending from the Taunus mountains Aar (Dill), a tributary of Dill river in Germany, also in the basin of the Lahn Aar (Ill), a branch of the Ill river that separates from it in Strasbourg, France and rejoins it further north Aar (Twiste), a tributary of Twiste river in Germany, in the basin of the Weser Aar (village), a village in Rajasthan, India South American–Antarctic Ridge, also known as the American–Antarctic Ridge, a mid-ocean ridge in the South Atlantic Antarctica, IAAF code AAR
Military After-action review, a structured review process used by the U.S. military After action report, a retrospective analysis Assistant Automatic Rifleman, a soldier who carries ammunition; see Rifleman#Modern_tactics
Organizations All American Racers, a former Formula 1 and CART team Allens (law firm), a law firm (formerly known as Allens Arthur Robinson) American Academy in Rome, research and arts institution in Rome American Academy of Religion, an association of academics who research or teach topics related to religion Association for Automated Reasoning, a non-profit that seeks to advance the field of automated reasoning Association of American Railroads, an industry trade group representing the railroads of North America
Transportation AAR coupling, railway coupling specification of the Association of American Railroads AAR wheel arrangement, Association of American Railroads system for describing wheel arrangement of locomotives All-American Road, a designation for some national scenic byways in the US Ann Arbor Railroad (disambiguation)
Other uses Aar (Star Wars), fictional planet in Star Wars universe Aar, a fictional planet of the star Deneb, in the "Captain Future" stories The All-American Rejects, an American rock band Air America Radio, a domestic US radio network Average accounting return, a capital budgeting investment rule Adam's apple reduction, a surgery Afar language (ISO 639 language identification code) African American Review, a journal Amino acid response, the biochemical response of a mammalian cell starved of amino acids "At any rate"; see List of SMS abbreviations Alkali–aggregate reaction, a chemical reaction leading to expansion in concrete
See also Ahr, a river in Germany, tributary of the Rhine Aare (disambiguation)