Who Is Cat Grant’s Mother Katherine On ‘Supergirl’?

In the Supergirl episode “Red Faced,” while Kara (Melissa Benoist) must fight Red Tornado, a military cyborg that’s gone rogue, “The Queen of All Media” Cat Grant (Calista Flockhart) is shaken by a visit from her super judgmental mother, Katherine. She’s in town for a book tour (she’s an editor of books) but doesn’t have time to visit her grandson Carter.

[Who Is Supergirl’s Sister Alex?]

Katherine Grant is portrayed by Joan Juliet Buck. She’s best known for her roles in the films Julie & Julia (Madame Brassart) and Learning to Drive (Ruth) with Patricia Clarkson and Ben Kingsley. The former child actress is also recognized for her role as Ailie in the 1961 Disney film Greyfriars Bobby: The True Story of a Dog. Supergirl airs Mondays at 8pm on CBS.