The Game of Thrones star's character is being kept under wraps for the time being, but the website notes that "Clarke's role will round out a dynamic cast of characters that Han and Chewie will encounter on their adventures."
Clarke will act opposite Alden Ehrenreich and Donald Glover, who will play Han Solo and Lando Calrissian, respectively, in the new film, which is set prior to the first Star Wars trilogy.
ET caught up with Ehrenreich just last week, where he raved about Glover's addition to the cast.
"I'm really excited to work with him," he exclaimed. "I think he's going to be great in the role."
"He's such an interesting guy and a wonderful actor," Ehrenreich, 26, added. "He's just going to do something with that role that I think is going to be really exciting for everybody."