Emily O'Brien was in plays at Carlsbad High School, where she graduated in 2003, and at MiraCosta College, where she completed a theater major in 2005. In 2005, she graduated with a degree in theater from Mira Costa College.
She was named a finalist in the Kennedy Center American College Theater Festival’s Irene Ryan Acting Competition in 2005, where she was pitted against several hundred students from colleges and universities across the country. She attended Guildhall School of Music and Drama in London, England and wrote, produced and directed her first project Beatrice in 2011 which won best film at BIFF.
She portrayed Jana Hawkes Fisher in The Young and the Restless. O'Brien was nominated for three Daytime Emmy Awards for her performance in The Young and the Restless. She portrayed the role again in November 2008, when a parody of the show was the theme of the 1st showcase on The Price Is Right. O'Brien portrayed the role initially on a recurring status from 11 May to 5 September 2006,[2] and then on contract from 10 October 2006 to 20 February 2007,[3] when the character disappeared from the canvas temporarily until her return on 15 June 2007.[4] O'Brien earned two Daytime Emmy Award nominations for Outstanding Younger Actress in 2008 and 2009.[5][6] In March 2011, news broke that O'Brien had been let go from The Young and the Restless,[7] with her final airdate on 6 May 2011. Prior to her dismissal, O'Brien was pre-nominated for another Daytime Emmy in the same category.[8]
O'Brien appeared in Hideo Kojima's 2019 game Death Stranding[14] as the voices of Bridget and the young Amelie Strand, characters using the likeness of Lindsay Wagner. She has several projects in hand that are currently in post-production, like Vampire Dad, Iris, and Beautifully Flawed.
In May 2020, it was announced that O'Brien had joined the cast of Days of Our Lives in the role of Gwen Rizczech. She made her first appearance on 1 June of the same year.[15]
On October 2, 2023, it was announced she would assume the role of Theresa Donovan on Days of Our Lives.[16]
In November 2024, it was announced O'Brien would return to play her iconic character Theresa in March 2025, before reprising her role Gwen Rizczech in July 2025 on Days of Our Lives.[17]
