The official IAU three-letter abbreviation for Orion is Ori.
The International Astronomical Union uses standardized three-letter abbreviations to identify the 88 modern constellations. Orion’s abbreviation is “Ori,” derived from the constellation’s Latin name, Orion. It appears in astronomical designations such as α Ori for Betelgeuse and β Ori for Rigel.
The abbreviation should not be confused with an informal shortening, a star’s proper name, or Orionis, the constellation’s Latin genitive form. Orionis is used in full star designations, while Ori is the compact constellation code used in catalogs and databases. The IAU adopted the modern abbreviation system in 1922.
Orion is one of the sky’s most recognizable constellations and was included among Ptolemy’s 48 ancient constellations. Its famous Belt consists of Alnitak, Alnilam, and Mintaka. The constellation also contains the Orion Nebula and gives its name to the Orionid meteor shower, whose parent body is Halley’s Comet. The abbreviation therefore identifies the constellation, not the mythical hunter or any single star.