Motley Crue's Vince Neil: I'm with Ahnald! First to Join New 'Celebrity Apprentice'

Vince Neil is the first contestant to sign on for the new 'Celebrity Apprentice' with Arnold Schwarzenegger in the boss' chair ... TMZ has learned.

Since NBC announced Schwarzenegger would replace Donald Trump -- the network has been gearing up for new contestants, and Vince jumped at the opportunity.

The Motley Crue frontman just finished the band's 'Final Tour' on December 31 ... and is ready to transition to a reality TV star.