Comic-Con: Supergirl season 4 trailer takes off! During their annual San Diego Comic-Con panel, The CW released the first official Supergirl season 4 trailer! Check it out in the player below and let us know what you think. Season 4 will premiere on the CW on Sunday, October 14th, at 8 PM ET. New additions to the series also announced include: Nicole Maines, as Nia Nal, the newest addition to the CatCo reporting team.