Billy Crystal: I'm Hosting the Oscars!

Billy Crystal just announced ... he's replacing Eddie Murphy as the host for next year's Oscars show.

The legendary Academy Awards host tweeted just minutes ago -- "Am doing the Oscars so the young woman in the pharmacy will stop asking my name when I pick up my prescriptions. Looking forward to the show."

As we previously reported, Murphy backed out from hosting the show yesterday -- after his friend Brett Ratner resigned from producing it ... following uproar over a homophobic slur Ratner dropped at a film screening.

This will be Crystal's 9th time hosting the Oscars.