It is set in the Arrowverse, sharing continuity with the other television series of the universe. The season is produced by Berlanti Productions, Warner Bros. Television, and DC Entertainment, with Robert Rovner and Jessica Queller serving as showrunners.
Production began that July and concluded in April 2019. Melissa Benoist stars as Kara, with principal cast members Mehcad Brooks, Chyler Leigh, David Harewood, and Katie McGrath also returning from previous seasons, while Jesse Rath was promoted to the principal cast from his recurring status in season three. They are joined by new cast members Sam Witwer, Nicole Maines, and April Parker Jones.
Former series regular Calista Flockhart makes an uncredited guest appearance in the third episode.
The series was renewed for a fifth season on January 31, 2019.