Finneran appeared in the original cast of Love, Loss, and What I Wore, which opened Off-Broadway at the Westside Theater in September 19, 2009 for a four-week engagement ending on October 18, 2009. The play "....is performed by a rotating cast of five. For the first four weeks of the run Ms. [Rosie] O’Donnell is joined by the actresses Tyne Daly, Katie Finneran and Natasha Lyonne, and Samantha Bee..." Finneran returned to the show (after her initial four-week engagement) on November 18, 2009, to fill in for Kristen Chenoweth, and continued on in the play in the next four-week rotation as well (from December 14, 2009 to January 3, 2010). She appeared in the first Broadway revival of the musical Promises, Promises as Marge MacDougall, opposite Kristin Chenoweth and Sean Hayes. The show opened March 27, 2010 and Finneran left the show on October 10, 2010 due to her pregnancy. She won the 2010 Tony Award for Best Featured Actress in a Musical for this role.