Jimmy Fallon's 'Tonight Show' Debut: Hollywood Reacts

Justin Timberlake, Ellen DeGeneres, Hugh Jackman and James Van Der Beek were among the stars wishing Fallon well on his new gig.
Jimmy Fallon interviewing Will Smith on his first episode of "The Tonight Show"

Jimmy Fallon began his Tonight Show career with a slew of stars, including Tina Fey, Robert DeNiro, Lady Gaga, Joan Rivers, Mike Tyson, Joe Namath, Seth Rogen and Stephen Colbert, as well as first guests Will Smith and U2.

PHOTOS: Hollywood Stars Join Jimmy Fallon For His 'Tonight Show' Debut

With Fallon and Smith kicking it up a notch with "Evolution of Hip-Hop Dancing" and U2's rooftop performance of "Invisible," the new Tonight Show era was off to a blazing start.

Here is what Hollywood had to say about the first Tonight Show.