Willis becomes the third actor to play Garthy, the eldest son of Tracey Stubbs.
He follows Simon Nash and Matt Savage who played the role in the original series.
Charlie Quirke will play Tracey’s younger son Travis who born in the final scene of the last episode from the original show.
The actor played the same part in a successful stage production of the show which toured the UK earlier this year.
The pair join original actresses Linda Robson, Pauline Quirke and Lesley Joseph who reprise their roles as Tracey, Sharon and Dorian.
Original writers Laurence Marks and Maurice Gran with Gary Lawson and John Phelps have penned the new series which is due to air Spring 2014.
Matt Willis said: “I’m so excited to be joining Birds of a Feather playing the role of Garthy! I used to watch the show growing up so this is just a dream job. I can’t believe I’ll be spending each day at work with Sharon, Tracey (aka Mum) and Dorian”.
Charlie Quirke said: “For me it’s great to get this opportunity after playing Travis on the stage tour for the last two years, and it’s great working with the two girls again & mum!”