"Congratulations Jimmy. I hope you're as lucky as me and hold on to the job until you're the old guy," Leno says in a statement. "If you need me, I'll be at the garage."
Says Fallon: "I'm really excited to host a show that starts today instead of tomorrow."
As reported earlier this month, The Tonight Show will return to 30 Rock in New York. Saturday Night Live boss Lorne Michaels will serve as executive producer.
"Jay Leno is an entertainment icon, making millions of people laugh every weeknight for more than 20 years," Steve Burke, Chief Executive Officer of NBCUniversal says. "His long reign as the highest-rated late-night host is a testament to his work ethic and dedication to his viewers and to NBC. We are purposefully making this change when Jay is number one, just as Jay replaced Johnny Carson when he was number one. Jimmy Fallon is a unique talent and this is his time. I'm thrilled he will become the sixth host of The Tonight Show at exactly the right moment, in conjunction with our coverage of next year's Winter Olympic Games from Sochi, Russia."
As for Fallon's replacement, rumor has it that SNL vet Seth Meyers is the top choice.