Season 4 (Supergirl)

The fourth season of premiered on October 14, 2018, on The CW and concluded on May 19, 2019. The season consisted of 22 episodes.

Synopsis
Season Three saw Supergirl stop Reign and the other Worldkillers' threat to humanity and our planet, and in the process, Kara was shocked to find her mother Alura alive and living in a salvaged Argo City that survived the destruction of Krypton. Reconnecting with her past caused Kara to realize that her true home is now here on Earth, where big changes are taking place for her and all of her friends in National City – and also, it appears, for a doppelganger in Russia! With a wave of anti-alien sentiment roiling the country led by Agent Liberty; and a new command at the DEO, Colonel Haley – Kara returns to CatCo, where she mentors young reporter Nia Nal, who evolves into a superhero herself. Season four promises to be full of surprises, action, adventure and lots of big revelations for Supergirl, Alex, James, J'onn, Lena, and Brainiac-5.

Main Cast

 * Melissa Benoist as Supergirl (Kara Danvers) / Red Daughter
 * Mehcad Brooks as Guardian (James Olsen) / Jimmy
 * Chyler Leigh as Alex Danvers / Alex Danvers
 * Katie McGrath as Lena Luthor
 * Jesse Rath as Brainiac 5/Barney Fife (Querl Dox)
 * Sam Witwer as Agent Liberty (Ben Lockwood)
 * Nicole Maines as Dreamer (Nia Nal)
 * April Parker Jones as Lauren Haley
 * David Harewood as Martian Manhunter (J'onn J'onzz)

Recurring Cast

 * Lynda Carter as President Olivia Marsdin
 * Jon Cryer as Lex Luthor
 * Brenda Strong as Lillian Luthor
 * Rhona Mitra as Mercy Graves
 * Robert Baker as Metallo (Otis Graves)
 * Tiya Sircar as Fiona Byrne
 * Anthony Konechny as Parasite (Raymond Jensen)
 * Jaymee Mak as Mackenzie
 * Bruce Boxleitner as (Vice) President Phil Baker
 * Andrea Brooks as Eve Teschmacher
 * Sarah Smyth as Lydia Lockwood
 * Graham Verchere as George Lockwood
 * David Ajala as Manchester Black
 * Donna Benedicto as Agent Reiff
 * Steve Byers as Tom
 * Roxy Wood as Yvette Turner
 * Jessica Meraz as Menagerie (Pamela Ferrer)
 * Louis Ozawa Changchien as Hat
 * Azie Tesfai as Kelly Olsen
 * Françoise Robertson as Sarah Walker

Soundtrack
On June 4, 2021, an album consisting of incidental music from the season was released digitally on Spotify and Amazon Music.