The show, provisionally titled Autumn Leaves, was announced by BBC One controller Danny Cohen when he spoke at the Edinburgh TV Festival earlier today (August 24).
The Little Britain star has co-written the programme with the Dawson Brothers, who have previously worked on That Mitchell and Webb Look, The Jonathan Ross Show and Lee Mack's All Star Cast.
Walliams said: "I am delighted to be back at the BBC, writing and acting in a new sitcom.
"The Dawson Brothers are brilliant. I met them when they wrote sketches for The One Ronnie and I have loved collaborating with them.
"The read-through of the first episode attracted a stellar cast, and I hope the series will too."
Consisting of six half-hour episodes and airing on BBC One, Autumn Leaves is described as a cross between Grange Hill and The Remains of the Day.
