[4] She is best known for her roles as Abby Newman on The Young and the Restless and The Bold and the Beautiful,[5][6] Penny Scavo on Desperate Housewives,[7][8] Princess Amber on Sofia the First[9] and Elena and the Secret of Avalor,[10] Ikki on The Legend of Korra,[11][12] and Maricela in Spirit Riding Free.

[15] In May of 2024, Darcy Rose Byrnes began her run as Mary Lane in the 25th Anniversary production of Reefer Madness: The Musical at The Whitley on Hollywood Blvd.

As she was too young to be a full-time undergraduate student, she enrolled in the eight-week Shakespeare programme at the Royal Academy of Dramatic Art (RADA) in London.

[17][18] Byrnes appeared in the direct-to-video film The Sparky Chronicles: The Map in 2003, the same year she obtained a role in the soap opera The Young and the Restless as Abby Newman from 2003 to 2008.

Byrnes also has appeared in television shows including How I Met Your Mother,[20] Ghost Whisperer, Cold Case,[21] Dirty Sexy Money,[22] and House.