Season 4 (Supergirl)

"Never give in. Never, in nothing, great or small, large or petty, except in considerations of honor and good sense. Never yield to force, or the apparently overwhelming might of the enemy that confronts you. Never. Never, ever, give in."

- Ben Lockwood

​​​​ was renewed for a fourth season by The CW on April 2, 2018. It premiered on October 14, 2018.

Main cast

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

Recurring cast

 * Lynda Carter as President Olivia Marsdin
 * Jon Cryer as Lex Luthor
 * Brenda Strong as Dr. Lillian Luthor
 * Rhona Mitra as Mercy Graves
 * Robert Baker as Otis Graves/Metallo
 * Tiya Sircar as Fiona Byrne
 * Anthony Konechny as Raymond Jensen/Parasite
 * Jaymee Mak as Mackenzie
 * Bruce Boxleitner as Vice President/President 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
 * Jessica Meraz as Pamela Ferrer/Menagerie
 * Louis Ozawa Changchien as The Hat
 * Azie Tesfai as Dr. Kelly Olsen
 * Francoise Robertson as Sarah Walker

Confirmed plot points

 * The theme of the season is, "What Is Stronger; Hope or Fear?"
 * Ben Lockwood/Agent Liberty and Lex Luthor are the main antagonists of the season.
 * Lex Luthor will return in "The Quest for Peace".
 * James will exact his revenge on Lex Luthor for being shot.
 * Eve Teschmacher's backstory will be explored.

Trivia

 * This season airs on Sundays at 8/7c, as opposed to the past three seasons, where it aired on Mondays at the same time.
 * Manchester Black was originally going to be the main antagonist of this season.
 * Jeremy Jordan was supposed to appear in a recurring role this season, but unfortunately he was unable to. He will possibly appear in the fifth season.
 * This also means that this is the first season without Jeremy Jordan (Winn Schott) being featured in any shape or capacity.
 * This is the first season of Supergirl to have humans as main antagonists.