Kanye West's fiancée took part in a Sound of Music-themed Farewell song, with special lyrics just for Jay.
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Her lines were: "So long farewell last night I told my folks, now I won't be the butt of Leno's Jokes," which drew laugh's and smiles from the TV host.
Kim was just one of several stars taking part. Jack Black kicked off the ditty, singing: "if Fallon tanks you'll be back here next year," referring to the new host Jimmy Fallon.
Meanwhile Big Bang Theory star Jim Parsons sang: "your success is called the big chin theory."
One of the biggest cheers came for chat show queen Oprah Winfrey. She sang: "You really raised the bar if you were me you'd buy them all a car," referencing her famous giveaways, including one where she gifted cars to every delighted member of the audience.
Sheryl Crow's musical effort included the words: "I want to get on Dave," talking about Jay's rival David Letterman.
The extravaganza marked the end of a 22-year stint as one of America's top chat show hosts.
Jay took over the helm of The Tonight Show in 1992, leaving in 2009 to host his own The Jay Leno Show. He returned the following year after his predecessor Conan O'Brian left.
As he said his final farewells during his final show on Thursday, Jay had tears in his eyes. The presenter had admitted earlier in the show: "I don't like goodbyes - NBC does. I don't care for them."
He added: "When I started Justin Bieber wasn't even born yet, that's why we called it the good old days."