The restaurant will bring its ‘naughty but nice’ menu to the first floor food court area later this year.
It comes just two years after husband and wife team Paul Hemings and Cara Ceppetelli opened the first BIRD in Shoreditch in 2014.
Ceppetelli said: “It’s been an incredible two years for BIRD and Westfield Stratford City presents an exciting opportunity to expand our brand.
“Londoners have really embraced what we are about - high quality, free-range fried chicken the way it’s meant to be - and we look forward to bringing this ethos to our Stratford site.”
BIRD aims to offer a new twist on the ‘better burger’ craze by using chicken instead of beef, with dishes including a Waffle Burger and an Ice Cream Sandwich Doughnut.
It opened its second and third restaurants in Highbury & Islington and Camden in late 2015.
Ceppetelli and Hemings told BigHospitality last year that they were eager to continue growing the brand ‘both inside and outside London…if the opportunities arise’.