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's 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 SVU's 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.
