NBC has settled on two new stars for “The Tonight Show”: Jimmy Fallon and New York City.

The network has made a commitment to Mr. Fallon, the current host of its “Late Night” program, for him to succeed Jay Leno as the next host of “Tonight,” according to several senior television executives involved in the decision. As part of the agreement, the show would move from Burbank, Calif., back to New York, where it started in 1954 with Steve Allen as host.

NBC has not completed a deal with Mr. Fallon yet, but his assent is considered mostly a formality, since the move would represent a significant step up for him. And the network has not settled on an exact timetable for the switch, though it is expected to take place by fall 2014 at the latest, said the executives, who spoke on the condition of anonymity because discussions were still continuing.

One senior executive who has been involved in the discussions said on Wednesday that “there is no way on earth that this is not going to happen.”

The move to Mr. Fallon would be a significant cultural, and geographic, shift. Mr. Leno delivers a more traditional Las Vegas-style comedy act that is viewed as a link to previous hosts, including his immediate predecessor, Johnny Carson. Mr. Fallon, 38, offers a more contemporary and varied brand of entertainment, with a heavy reliance on the Internet. His best material gains additional life on sites like YouTube, and he actively courts interaction with his viewers by having them submit comedy ideas through Twitter.