By Agence France-Presse
The Tinseltown press first reported the casting news this week, with The Hollywood Reporter saying the 52-year-old Frenchman would be playing a villain.
"Westworld" unfolds in a near-future amusement park of sorts, where guests interact with androids in various settings and anything goes. But gradually, some of the androids start fighting back.
The series stars Evan Rachel Wood, Thandie Newton, Jeffrey Wright and Ed Harris. Also joining the cast for the new season are "Breaking Bad" alum Aaron Paul and actress-writer Lena Waithe.
"We're incredibly excited to work with Vincent Cassel," show creators Jonathan Nolan and Lisa Joy said in a statement released by HBO.
"We've been longtime fans of his and are thrilled for him to join the Westworld team."
Cassel's breakthrough role came in 1995 with "La Haine," a searing portrayal of life in Paris's racially polarized suburbs.
A series of big-screen roles followed in France, and then Cassel crossed over to Hollywood with featured parts in heist capers "Ocean's Twelve" and "Ocean's Thirteen."
He starred alongside Oscar winner Natalie Portman in the dark psychodrama "Black Swan."
In 2009, Cassel won the Cesar -- France's Oscars -- for best actor for his portrayal of legendary French gangster Jacques Mesrine in a two-part film.