Osbourne completes a three-strong presenting team, which also includes Jamie Theakston and Amanda Byram.
Sky's live coverage begins on Sunday, February 27 with a preview show at 7pm on Sky One. Updates continue through the evening on Sky Movies 1 ahead of the ceremony itself, which airs on the channel from 1am.
Theakston will be charged with covering the post-Oscars party scene live from the red carpet, while Byram and Osbourne undertake main hosting duties from the studio.
Sky won back the broadcast rights to the Oscars after a three-year tenure at the BBC.