After college, Giddish moved to New York City to pursue an acting career. Within a year, she landed a role in a
Broadway play with
Farrah Fawcett.
2005–2010: Early career Giddish portrayed
Diana Henry on soap opera
All My Children from 2005 to 2007. In July 2007,
Soap Opera Weekly magazine confirmed that Giddish and
All My Children parted ways in a mutual decision and that she would make her final appearance as Di on September 19, 2007. She appeared in the thriller film
Death in Love (2008), which premiered at the
Sundance Film Festival. She played the role of Courtney in the web series
The Burg, credited as the first scripted web series. The same people responsible for
The Burg also created ''All's Faire'', in which Giddish played the role of Cindy. Giddish,
Nicholas Bishop, and
Ravi Patel were cast in
Fox's
reincarnation drama pilot
Past Life. The
Warner Bros.-produced project revolved around past-life investigators. Giddish played a
Ph.D. in psychology and cognitive research who believes in reincarnation. On May 18, 2009, Fox announced that it had ordered
Past Life to series, airing midseason 2010 at 9:00 PM EST on Tuesdays. It premiered on February 9, 2010, but was canceled on February 18. Giddish starred as the central character,
U.S. Marshal Annie Frost, in the police procedural drama
Chase, which premiered on
NBC in autumn 2010. Giddish received rave reviews for her performances, but the show was pulled in early February 2011. On April 6, 2011, NBC decided to broadcast five unaired episodes of
Chase on Saturday nights, with the first beginning on April 23, 2011.
2011–present: Law & Order: Special Victims Unit In January 2007, Giddish guest starred on
Law & Order: Special Victims Unit in the episode "
Outsider" as rape victim Kara Bawson. It was announced on June 27, 2011, that Giddish would join the cast of
Law & Order: Special Victims Unit for its
thirteenth season along with
Cold Case Danny Pino coinciding with
Christopher Meloni's departure from the series. Giddish told
TV Guide during summer filming, "They've lost a family member with Chris Meloni leaving, but they've been very accepting of us.
Detective Amanda [Rollins, her character on the show] is thrilled to be here working with these people, and so am I." Giddish made her debut as Rollins in the 13th-season premiere, "
Scorched Earth", in which the character first works alongside Detective
Olivia Benson (
Mariska Hargitay). Giddish expressed confidence that viewers would warm up to Rollins and another new character,
Nick Amaro (Pino), with time. At the end of the series' Season 13, she said she and Pino received not only a "very warm welcome" from
SVUs cast and crew, but saw their respective characters explored more than they could hope for in their first season. "They've given me a lot to work with — and I hope they give me more next season," says Giddish. "We're still playing 'musical chairs' in terms of partners, and that's a great way to go about exploring the different characters." On April 16, 2020, Giddish's character was promoted to 2nd grade class detective, in "
Solving for the Unknowns". Giddish's initial departure as a regular cast member was season 24, episode 9 ("And a Trauma in a Pear Tree") in which Rollins married ADA Dominick Carisi Jr. (
Peter Scanavino) and resigned from the Special Victims Unit to accept an offer to teach at
Fordham University. She returned as a special guest star in season 24, episode 22 (
"All Pain Is One Malady"), season 25, episode 1 ("Tunnel Blind") and episode 11 ("Prima Nocta"), season 26, episode 3 ("Divide and Conquer"), episode 8 ("Cornered"), episode 9 ("First Light"), episode 16, ("Accomplice Liability") and episode 20 ("Shock Collar"). After her last episode as a regular on SVU in 2022, she also appeared in the third season of the spin-off
Law & Order: Organized Crime assisting
Elliot Stabler on a case in episodes 21 ("Shadowerk") and 22 ("With Many Names"), the latter of which aired as a crossover event with the 24th season of SVU. Starting September 2025, Giddish returned as a series regular for the 27th season, after the show received harsh criticism from cast members, and the audience for letting her go. ==Other works==