The project focuses on famous fashion designer Robert Soulter and his family, who are shaken up by the arrival of young designer Alice Clarke.
Alpay has now signed up to play Robert's son Jesse in the drama, Deadline says.
Jesse, the oldest son in the family, has recently been promoted and is now the co-president of the family's label.
Alpay has previously appeared in The Tudors and will star in the upcoming second season of The Borgias. He has also had guest roles in shows such as Dollhouse, Fairly Legal and Rizzoli & Isles.
Anthony LaPaglia has already signed up to play Alpay's on-screen father Robert in Americana, while Twilight's Ashley Greene will take on the role of Alice.
The cast also includes stars such as Ken Olin, Natalie Mendoza, Christine Adams, Annabeth Gish and Emilie De Ravin.