Luke Wilson has joined the cast of Kevin Costner's new Western movie 'Horizon'.

The 50-year-old actor has boarded the ensemble cast of the film that Costner is both starring in and directing.

The 'Field of Dreams' star will also produce the movie through his Territory Pictures Inc., and he has written the script with Jon Baird.

Sienna Miller, Sam Worthington and Jamie Campbell Bower are also on board to star in the flick, which is being developed by Warner Bros. and New Line.

'Horizon' tells the story of the 15-year span of pre-and-post Civil War expansion and settlement of the American West.

Told through the eyes of many, the epic journey is full of peril and intrigue from the constant onslaught of natural elements to interactions with indigenous people who lived on the land, and the determination and ruthlessness of those who wanted to settle on it.

The movie marks the first time Costner has directed a film since 2003 and sees him revisit Civil War-era America – the setting for his 1990 Oscar-winning directorial debut 'Dances With Wolves'.

Sources say that Wilson was one of the first actors to sign up for the project after forming a good relationship with Costner, with the star quickly offering him a role.

Luke played Emmett Richmond in the 'Legally Blonde' movies and revealed that he wants to return for the planned third film.

He said: "Of course [I'd do it]. As for the 'Legally Blonde' that we’re hearing about now — I don’t know anything than the usual man on the street.

"And that’s really the truth. I’ve heard they’re writing it and trying to put it together, but they’re keeping it pretty firmly under wraps."