Cheer up, Leo!

Leonardo DiCaprio looked like a very unhappy camper heading to work in Sydney, Australia on Thursday.

Filming The Great Gatsby, the 36-year-old actor was photographed in the backseat of a chauffeured car -- hanging out of the window with a ponderous, forlorn expression.

Two days ago, Us Weekly broke news of DiCaprio's split from Blake Lively after five high-flying months together.

DiCaprio's long shoot in Australia -- as Lively films Gossip Girl and the flick Savages in the U.S. -- certainly didn't help the relationship, a pal says.

Thanks to the 7,000-plus-mile distance, "there's a 12-hour time difference just to chat on the phone," a pal explains in the new Us Weekly.

Tell Us: Who should DiCaprio date next?