Happy Birthday, Ellen!

Ellen DeGeneres is throwing herself a big 50th birthday bash tonight. We've got all party details, including the star-studded guest list

Yep, she’s 50!

Ellen DeGeneres is celebrating the big 5-0 with a star-studded blowout carnival and casino-themed bash tonight on the Warner Bros. lot in Burbank.

I'm told that the 600 or so on the guest list include newlyweds Mariah Carey and Nick Cannon, Tom Cruise, Katie Holmes, Tom Hanks, Lindsay Lohan, Jamie Foxx, Paris Hilton and Clive Davis.

Pink will perform and Samantha Ronson will deejay.

DeGeneres turned 50 on Jan. 26, but postponed her party plans because of the writers' strike.