The film will see ineffectual teacher Alfie Wickers travelling to Cornwall with the students he used to teach.
Whitehall will reprise his role was Wickers, with a picture released featuring the cast on location confirming that Ethan Lawrence will return as Joe, Nikki Runeckles as Chantelle, Layton Williams as Stephen, Charlie Wernham as Mitchell, Jack Binstead as Rem Dogg, Kae Alexander as Jing and Weruche Opia as Cleopatra.
Ben Cavey, the sitcom's Executive Producer, confirmed on Twitter: "It's only ruddy happening."
The film follows the end of the BBC sitcom, which concluded in October after three series. The emotional final episode saw the students coming to the end of their time at Abbey Grove school and Alfie deciding that he couldn't go on teaching without his beloved class.
The production details for the film have not yet been officially revealed, but it is believed the project is being produced by Tiger Aspect - the same company that made the TV series. The script has reportedly been written by Freddy Syborn and Jack Whitehall, with Ben Cavey as Producer and Elliot Hegarty as Director.
The producers will be hoping to emulate the big-screen success of The Inbetweeners. The E4 sitcom took over £40 million at the box office when it transferred to the big screen with its first film in 2011.
Further details about the film are expected to be revealed shortly.