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


Main cast

Special guest cast

Recurring cast

Confirmed plot points

  • There will be an Elseworlds crossover with The Flash and Arrow. The crossover will introduce Batwoman and Gotham City.[9]
  • Journalism is going to be a big part of the season.[10]
  • The theme of the season is, "What Is Stronger; Hope or Fear?"[10]
  • The Red Son-ish cliffhanger from the Season 3 finale will become a big centerpiece in the latter part of the season.[10]
  • This season, Brainiac will socially butt heads with a couple people.[10]
  • Mehcad Brooks hinted that there will be "fallout" from James choosing to unmask himself as Guardian last season.[10]
  • What will the characters make of Kate Kane aka Batwoman, in this December's Arrowverse crossover? "I think Alex might really like her", EP Sarah Schechter surmised with a smile. "I think strong women like each other, and strong women support each other. They definitely have very different ways of behaving in the world, but I think, ultimately, they'll agree that women should be in charge".[10]
  • David Harewood will direct an episode this season.[11]
  • Lex Luthor will be introduced this season with casting underway.[6]
  • James Olsen's sister will appear this season.[7]
  • Nia Nal's mother and sister will appear this season.[8]

Confirmed new characters

  • Lois Lane: Described as the daughter of U.S. General Sam Lane, Lois is a tenacious, righteous and stubborn reporter who will go to any length to get the story and almost never fails.[12]
  • Mar Novu/The Monitor: An extraterrestrial being of infinite power.[5]
  • John Deegan: A doctor at Arkham Asylum for the Criminally Insane in Gotham City, but he might just be crazier than the inmates he treats. His machinations will draw Green Arrow, the Flash and Supergirl to Gotham City.[13]
  • Lex Luthor: He will shake things up in National City and go toe to toe with not only Supergirl, but his sister Lena Luthor.[6]
  • Kelly Olsen: Kelly is an intelligent and insightful woman who spent time in the military in order to pay for medical school. She's recently discharged from the military and is currently finishing her training as a psychiatrist. She's got a large heart and cares deeply about others.[7]
  • Maeve Nal: Driven and focused on maintaining the Nal family’s rich legacy. She and Nia have a strong sisterly bond, although Maeve has always had to work harder to achieve what comes naturally to Nia.[8]
  • Isabel Nal: The warm and nurturing mother of Nia Nal, is a local hero in her own right. She is a wise and generous matriarch and has raised her family to be bold and courageous, as well as to love fiercely and openly.[8]


  • This season airs on Sundays at 8/7c, as opposed to the past three seasons, where it aired on Mondays at the same time.
  • Season 4 is the first season to introduce a live-action transgender superhero.


# Episode name Directed by Story by Teleplay by Original airdate
1 "The American Alien" Jesse Warn Robert Rovner & Jessica Queller Gabriel Llanas & Aadrita Mukerji October 14, 2018
Diving back into reporting, Kara welcomes a new cub reporter to CatCo. Meanwhile, James and Lena argue about James' impending indictment for acting as the vigilante Guardian, while Alex and Brainy struggle to get in sync at the DEO. Supergirl is called into action when remnants of the anti-alien terrorist organization Cadmus try to assassinate pro-alien leaders, but their endgame turns out to be much more sinister than she expected. J'onn relishes his peaceful new life, but an outing with an old friend causes him concern.
2 "Fallout" Harry Jierjian Dana Horgan Maria Maggenti & Daniel Beaty October 21, 2018
A shocking revelation causes chaos in National City. Supergirl sets out to capture Mercy Graves, while Alex takes control at the DEO. Back at CatCo, Kara decides to write an investigative story on Mercy and asks Lena if she can interview her as Mercy has ties to the Luthors. Meanwhile, Brainy meets Nia and the two end up in a precarious situation.
3 "Man of Steel" Jesse Warn Robin Wright & Derek Simon October 28, 2018
Ben Lockwood didn't always hate aliens. Through a series of incidents, and input from his anti-alien father, Ben slowly transforms from a mild-mannered professor into the villainous Agent Liberty of today.
4 "Ahimsa" Armen Kevorkian Eric Carrasco Katie Rose Rogers & Jess Kardos November 4, 2018
When Supergirl needs help, Alex asks Lena and Brainiac to team up; J'onn questions his decision to quit the DEO, but after running into Manchester Black, he realizes there are a lot of ways to help his fellow aliens.
5 "Parasite Lost" TBA TBA November 11, 2018
Colonel Haley makes a surprising decision regarding Supergirl. Kara writes a series of articles highlighting aliens in National City in the hopes that humans will stop being so fearful of them. Unfortunately, the article puts some of the aliens in harm’s way.
6 "Call to Action"[14] TBA TBA TBA
Everyone gathers for Thanksgiving but Kara is feeling down after her televised debate with Ben Lockwood about the anti-alien sentiment coursing through National City. Meanwhile, James and Lena argue about the best way to handle the Children of Liberty.[15]
7 "Rather the Fallen Angel"[14] TBA TBA TBA
8 "Bunker Hill"[16] TBA TBA TBA
9 "Elseworlds: Hour Three"[16] TBA TBA December 11, 2018[17]
10 "Secrets and Lies"[16] TBA TBA January 20, 2019[18]


Title cards

Promotional images


  1. Ruby Rose Cast as The CW's Batwoman -
  3. The CW Finds Its Lois Lane in 'Grimm' Star - The Hollywood Reporter
  4. Supergirl: Jeremy Jordan Shifts to Recurring Status in Season 4 - TV Line
  5. 5.0 5.1 LaMonica Garrett Joins ‘Arrowverse’ Crossover ‘Elseworlds’ - Variety
  6. 6.0 6.1 6.2 Lex Luthor Is Headed to Supergirl — Who Should Play the Iconic Big Bad? - TVLine
  7. 7.0 7.1 7.2 ‘Supergirl’: Azie Tesfai To Play James Olsen’s Sister On the CW’s DC Series - Deadline
  8. 8.0 8.1 8.2 8.3 "‘Supergirl’: Hannah James & Kate Burton Cast As Maeve & Isabel Nal In CW Series" - Deadline
  9. Next CW superhero crossover to introduce Batwoman - EW
  10. 10.0 10.1 10.2 10.3 10.4 10.5 Supergirl @ Comic-Con: 'Grounded' Season 4 Brings Back Kara the Reporter - TVLine
  11. David Harewood - Twitter
  12. EXCLUSIVE: Arrowverse Crossover Breakdown For Lois Lane! - ThatHashtagShow
  13. 'Lost' Star Jeremy Davies To Play Arkham Employee in Arrowverse Crossover -
  14. Cite error: Invalid <ref> tag; no text was provided for refs named 705.E2.80.93707_Titles
  15. "Supergirl - Episode 4.06 - Call to Action - Press Release" - SpoilerTV
  16. 16.0 16.1 16.2 "Supergirl - Episode 4.08 - 4.10 - Titles Revealed" - SpoilerTV
  17. "Arrowverse's 3-Night Crossover Featuring Batwoman: When Will It Air?" - TV Line
  18. "The CW January 2019 Midseason Schedule" - SpoilerTV