Supergirl was renewed for a sixth season by The CW on January 7, 2020. Due to the coronavirus pandemic, on May 14, 2020 the CW announced that their regular season would start in January 2021 rather than October 2020 as usual. Along with this, they announced that Supergirl would return midseason.
SUPERGIRL is an action-adventure drama based on the DC character Kara Zor-El. Thirteen-year-old Kara escaped the doomed planet Krypton and was sent to Earth where she was raised by a foster family. Kara grew up in the shadow of her foster sister, Alex, and learned to conceal the phenomenal powers she shares with her famous cousin, Superman, in order to keep her identity a secret. Years later, Kara was living in National City and still concealing her powers, when a plane crash threatened Alex's life and Kara took to the sky to save her. Now, Kara balances her work as a reporter for CatCo Worldwide Media with her work as Supergirl, keeping National City and the Earth safe from sinister threats. She's joined in this pursuit of justice by her sister, Alex, her mentor, Martian Manhunter and her friends Brainiac-5, Dreamer and Lena Luthor. As Kara struggles to navigate her relationships and her life as a reporter, her heart soars as she takes to the skies as Supergirl![src]
Due to being pushed to mid-season, this season could possibly have a reduced episode count than previous seasons such as most previous seasons had up to 22 episodes with the exception of season 5 which had 19.