She starred on Broadway as Billie Bendix in "Nice Work If You Can Get It" from April 2012 to March 2013 and received her fourth Tony Award nomination. In 2012, at the New Year's Eve concert, "Celebrating Marvin Hamlisch", at Lincoln Center, she sang "At the Ballet", from "A Chorus Line", along with Audra McDonald and Megan Hilty. In 2013, she played the lead character of Julie in the staged concert of "Carousel" presented by the New York Philharmonic at Avery Fisher Hall. From January to May 2014, she starred as Francesca Johnson in the Broadway musical "The Bridges of Madison County", for which she received her fifth Tony Award nomination. Elyse Sommer, the "CurtainUp.com" reviewer, noted O'Hara's "superb vocal chops" and her "exquisite" duets with co-star Steven Pasquale. She played Mrs. Darling in the 2014 NBC telecast "Peter Pan Live!". She sang two concerts, titled "Kelli and Matthew: Home for the Holidays", in December 2014 at Carnegie Hall with the New York Pops. On December 31, 2014, O'Hara made her operatic debut at The Metropolitan Opera as Valencienne in Franz Lehár's "The Merry Widow", alongside Renee Fleming in the title role.