Kim Basinger, Eric Johnson and Bella Heathcote have also recently joined the cast, with Dakota Johnson and Jamie Dornan returning to reprise their roles of Anastasia Steele and Grey, respectively. James Foley is taking over directing reins from Sam Taylor-Johnson.
Dancy will play Dr. Flynn, Grey's psychiatrist in the books.
Luke Grimes, Eloise Mumford and Max Martini are also returning to the cast, with Michael De Luca and Dana Brunetti producing along with author E.L. James and Marcus Viscidi. Niall Leonard and James are penning the script.
See photos of Dancy:
Universal is planning to shoot "Fifty Shades Darker" and the final pic, "Fifty Shades Freed," back-to-back, with "Darker" set to bow Feb. 10, 2017. "Darker" is currently in production.
Dancy currently stars on Hulu's drama "The Path" with Aaron Paul and Michelle Monaghan. He previously starred on NBC's "Hannibal" and he was nominated for an Emmy for his playing the Earl of Essex in HBO's miniseries "Elizabeth I."
He's repped by UTA, United Agents, Parseghian Planco and Jackoway Tyerman. The Hollywood Reporter first reported the news.