Olivia D’Abo’s film debut was the supporting role of Princess Jehnna in Conan the Destroyer, released on 29 June 1984. Two months later, she appeared in the supporting role of Paloma the peasant girl in Bolero (1984).
D’Abo portrayed Karen Arnold in the ABC comedy-drama series The Wonder Years for the show’s first four seasons, from 1988 to 1991, with two guest star appearances in the show’s final two seasons. In 1992, she guest-starred in the Star Trek: The Next Generation episode titled “True Q” as Amanda Rogers.
An unreleased pilot for an ABC sitcom she led, Olivia Masters’ Life, was released on her official website. The pilot shows young, tenacious American woman Olivia Masters as she tries to find her calling and acclimate herself into the professional world, which is not always professional or a breeze, as she finds out.
D’Abo made five appearances as a recurring villain Nicole Wallace in the NBC police procedural drama series Law & Order: Criminal Intent between 2002 and 2008. She reprised the character in the 2013 episode “The Catacombes” in the French police procedural drama series Jo, a show created by René Balcer, who also created Criminal Intent.
In 2007, D’Abo played Abby Carter, the ex-wife of Sheriff Jack Carter, in the Sci-Fi Channel series Eureka for two episodes. She has had numerous supporting roles in other television series and films, such as The Spirit of ’76 (1990), Greedy (1994), The Big Green (1995), and The Twilight Zone (2002). Onstage, she appeared in the 2005 Broadway theatrical production of The Odd Couple alongside Matthew Broderick and Nathan Lane.
In animation, D’Abo provided the voices of Sonya Blade in Mortal Kombat: Defenders of the Realm (1996); Melanie Walker/Ten in Batman Beyond (1999–2000); Star Sapphire in Justice League (2001); and Morgaine le Fey in Justice League Unlimited (2004); Tak in Invader Zim (2001–2002); Jane Porter in The Legend of Tarzan; Jedi Master Luminara Unduli in Star Wars: The Clone Wars (2008), which she reprised the character in the cameo role in Star Wars: The Rise of Skywalker (2019); Carol Ferris in Green Lantern: First Flight (2009); and Natalia Romanoff in Ultimate Avengers, and Ultimate Avengers 2: Rise of the Panther (both 2006).
In February 2013, D’Abo began filming for Tesla Effect: A Tex Murphy Adventure (working title: Project Fedora), a video game that combined live-action footage with 3D graphics.
D’Abo is a singer-songwriter, guitarist, and pianist. She has composed and performed for various soundtracks. Her single “Broken” is in the film Loving Annabelle. Her debut album, Not TV, was released in July 2008.
D’Abo also performed backing vocals for Julian Lennon’s Help Yourself, and a duet with Seal’s “Broken”. She also co-wrote the song “Love Comes from the Inside” with Italian singer Laura Pausini, which was featured on Pausini’s English-language debut album, From the Inside.
D’Abo performed a duet on Bon Jovi’s “Livin’ on a Prayer” for their 2003 acoustic album This Left Feels Right.