Deadline.com reported Tuesday (Jan. 8) that the actress will play Shaw, a witty and fearless operative in a secret paramilitary organization that tracks and eliminates terrorists before they can act.
View slideshow: "Fairly Legal" and "Chicago Fire" star Sarah Shahi
"If James Bond and Sarah Connor had a kid, Shaw would kick its ass," described "Person of Interest" creator Jonathan Nolan.
Shahi will first appear in the Feb. 21 episode, titled "Relevance." Her character will stick around for multiple episodes and may even return for Season 3.
The 32-year-old actress starred in the USA series "Fairly Legal" until it was officially cancelled in November.
She also has a recurring role on NBC's "Chicago Fire" as Kelly Severide's (Taylor Kinney) love interest.
"Person of Interest" continues Thursdays at 9/8 p.m. CST on CBS, while "Chicago Fire" airs Wednesdays at 10/9 p.m. CST on NBC.