Choking back tears for several minutes, Curry told viewers at the end of Thursday's program she would be leaving as co-host of the show and taking up a new role reporting from around the world for NBC.
"This is not as I ever expected, to leave this couch after 15 years. But I'm so grateful, especially to all of you who watch," Curry, 55, told viewers in a reluctant farewell surrounded by solemn co-hosts, including Matt Lauer.
"For all of you who saw me as a ground breaker, I am sorry I could not carry the ball across the finish line. But man, I did try."
Curry's departure from the early morning mainstay had been widely expected as she came under sharp scrutiny for the program's ratings decline.
The show did not announce who would replace her, but The Hollywood Reporter said the job had been offered to Savannah Guthrie, who hosts the show's third hour.
Curry said she would remain at NBC News as an international correspondent and would still appear on "Today," as well as participate in the network's coverage of the Summer Olympic Games, which begins on July 27.
Lauer, considered the star of the personality-driven show -whom analysts suspected did not have enough on-air chemistry with Curry - hugged and kissed her and told her, "It's not goodbye. Not by a long shot" and "You have the biggest heart in the business."
Since Curry moved from news reader to co-host of "Today" on June 9, 2011, the morning show's margin over ABC's "Good Morning America", or GMA, has steadily shrunk.
With former co-host Meredith Vieira sitting next to Lauer, the show had regularly beat "GMA" and led it by 650,000 viewers in the week before Curry replaced her, according to Nielsen numbers supplied by media planning and advertising agency Horizon Media.
GMA drew more viewers in four of the 10 weeks before June 11, 2011, among those who watched it live or recorded it on the same day.
Curry was Lauer's third co-host, following Vieira and Katie Couric, who preceded Lauer on the show and left in 2006 after 15 years to anchor CBS's evening news program.
The "Today" show is considered a huge profit center for NBC. Last year, it generated $848 million in advertising revenue for the company, making it one of the most profitable shows on television, according to Horizon Media. "Good Morning America" generated about $298 million.
Curry had succeeded Lauer as the early morning show's news anchor in 1997, when Lauer moved on to replace Bryant Gumbel as co-host.
Curry cried throughout her official announcement and apologized for being a "sob sister this morning."
"After all these years, I don't know if I can even sleep in anymore. I know that whatever time I wake up, I'll be missing you," she said.