Lauer has signed a long-term contract to remain as co-host of the No. 1 morning show, a long-anticipated deal that NBC announced Thursday night but Lauer made public on "Today" Friday morning.
"This is my family," he said on the air as the "Today" crew and co-anchors burst into applause.
"Truth be told," he joked, "I was developing an idea for a new show, where viewers could tune in every morning and see someone they know lose a little more of his hair every single day right in front of their eyes. But then I thought, I could just stay here and do that."
Although "Today" is on a historic winning streak in the ratings, "Good Morning America" has been gaining ground.
Lauer's decision provides important stability for "Today" and puts to rest suggestions that he might reunite with his former co-host Katie Couric on the syndicated show she's launching this fall.
Lauer said last May that he had discussed joining with Couric on a new venture. But he predicted then that he would be staying at "Today" for "a long time."
"Given how strong the 'Today' show has been, I don't think the outcome was ever in doubt," said industry analyst Larry Gerbrandt of Los Angeles-based Media Valuation Partners.
Lauer has been a fixture with the show since 1994 and began his run
"Today" has remained No. 1 in the weekly ratings since 1995.
Over at ABC, archrival "Good Morning America" gave Lauer an attaboy on its Friday telecast.
"Matt, you set the bar so high every day," said co-host George Stephanopoulos in voicing his congratulations.
Beside him sat Couric, who, now at ABC, has been subbing as co-host on "GMA" all week. She passed along her own greetings to her "old partner-in-crime," and announced that "GMA" had sent Lauer a bucket of golf balls as a gift.
"Take all the time off to perfect your golf game," Stephanopoulos proposed.
For broadcast networks, morning represents one of the most important parts of the day. The shows are hugely profitable at a time of declining TV viewership, and none has been more of a cash cow than "Today."
A recent report said Lauer could end up with a $25 million deal, but NBC President Steve Capus dismissed the speculation as "complete silliness," The New York Times said. NBC declined to provide further details Thursday on the contract.
The morning scene drew increased attention this week as the NBC and ABC programs featured dueling celebrity co-hosts: "Today" had Sarah Palin for a day, while Couric spent the week filling in at "GMA."
Flagged in advance, Lauer's announcement Friday was likely to also serve as a ratings stunt against his one-time colleague.
Palin, the former Alaska governor, helped "Today" maintain its winning streak against "GMA" on Tuesday, but Wednesday proved a cautionary tale for NBC. With Couric on board, "Good Morning America" was able to claim a one-day victory in viewership over "Today."
About 5.24 million viewers watched "GMA," while 5.15 million viewers tuned into "Today," according to the Nielsen Co.
ABC's advantage was the latest twist in a morning-show battle that has seen "GMA" chipping away at the ratings lead that "Today" has maintained every week for 16 years.
Overall last week, "GMA" shrank its gap behind "Today" to 119,000 viewers from 137,000 the previous week.
There had been some reports that "American Idol" host Ryan Seacrest could replace Lauer, and the two bantered about it Wednesday when Seacrest visited "Today" to announce he would take part in NBC's coverage of the Summer Olympics.
"What kind of conversations have you had with NBC officials about joining the 'Today' show?" Lauer asked Seacrest during a lighthearted exchange.
"Oh," said Seacrest, grinning, as off-camera laughter was heard from the crew. "They didn't tell you?"