The Gavin & Stacey star will play a down-on-his-luck father who "needs to find his inner Father Christmas to win back his kids" in the film School For Santas.
It will reunite him with writer Richard Bean - the playwright behind stage farce One Man, Two Guvnors, which gave James a best actor trophy at the Tony Awards - who will script the new film, being made by Working Title.
"To be making one with a company like Working Title Films is a dream come true."
Tim Bevan, who heads Working Title Films, said his company has "always loved Christmas and School For Santas feels like a gift".
It is due to start shooting next year in New York and London.