On June 25, 2018, it was announced that Toni Collette, Merritt Wever, and Kaitlyn Dever had been cast in the series' main roles.[12][13] On July 26, 2018, it was reported that Danielle Macdonald had joined the main cast.[14] In August 2018, it was announced that Kai Lennox, Austin Hébert, Dale Dickey, Omar Maskati, Elizabeth Marvel, Liza Lapira, and Eric Lange had been cast in recurring roles.[15][16][17] On September 26, 2018, it was reported that Vanessa Bell Calloway had joined the cast in a recurring capacity.[18]