The 43-year-old funnyman has signed up to appear as a visiting branch manager in four episodes of the NBC show alongside his Anchorman co-star Steve Carrell, who will be exiting from his role as cringe-worthy boss Michael Scott later this year.
Producer Paul Lieberstein said he invited the comic on the show to make Steve's departure bigger but joked that Will - who has acted, written and produced for many films and TV shows - needed more exposure.
He told Entertainment Weekly magazine: "We found Steve Carell when he was nothing but a movie star and we turned him into a television star. We are proud to continue The Office's tradition of discovering famous talent, and we hope that once America gets a good look at Will, they'll see what we see. Tremendous raw sexuality."
Earlier this month, it was reported that Ricky Gervais - who starred in the original, British version of The Office - will also be making a cameo appearance, revisiting his role of David Brent.
- BANG! Showbiz