The Naming of Orion
The constellation Orion was named after the Greek hunter Orion, who was put into the sky among the stars by Artemis after she was tricked into killing him by her brother Apollo. It is also thought that after a giant scorpion killed Orion, Artemis put the scorpion and Orion into the stars. She apparently made it so that Orion and the scorpion would always be on opposite sides of the sky which is how it got its name, The Orion.
The Origin of Orion
Orion's current name derives from Greek mythology, in which Orion was a gigantic, supernaturally strong hunter of ancient times, born to Eurayle, a Gorgon, and Poseidon (Neptune), god of the sea in the Greece-Roman tradition. One myth recounts Gaia's rage at Orion, who dared to say that he would kill every animal on the planet. The angry goddess tried to dispatch Orion with a scorpion. This is given as the reason that the constellations of Scorpius and Orion are never in the sky at the same time. However, Ophiuchus, the Serpent Bearer, revived Orion with an antidote. This is said to be the reason that the constellation of Ophiuchus stands midway between the Scorpion and the Hunter in the sky.