It's important to distinguish between the constellation itself and the mythological hunter it represents.
* The constellation Orion is a collection of stars that have been observed and named by humans for thousands of years. There's no single "age" for the stars themselves, as they formed at different times. Some stars are older, some younger.
* The mythological figure Orion is a character in Greek mythology, and his age is part of that story, usually portrayed as a young, strong hunter.
So, while we can't say how old Orion is, we can say that the constellation has been recognized and named for a very long time.
