Bandmates- Harry Styles, Liam Payne, Niall Horan, Zayn Malik and Louis Tomlinson - made the announcement during an appearance on an American chat show.
"We are going to do our first-ever movie and it's going to be in 3-D and it's coming to cinemas near you on the 30th of August, 2013," Niall said.
The film will be directed by filmmaker Morgan Spurlock, who is famous for making 'Super Size Me'.