Auerbach, 35, confirmed the news of Goodall's pregnancy on the red carpet of 57th Grammy Awards, reported E! Online.
While Goodall was all smiles as she debuted her bump in an embellished gold gown, Auerbach kept a hand on her baby belly in between posing for photos with his bandmate, Patrick Carney.
Auerbach is already father to six-year-old Sadie, his daughter with ex-wife Stephanie Gonis.
The Black Keys were nominated for best rock performance and best rock song for their song, 'Fever', losing to Jack White and Paramore respectively, and best rock album for Turn Blue, which ultimately was awarded to Beck.