Supergirl: Season 3
2017 · 23 episodes · ★ 7.1
What Season 3 of Supergirl
As season three returns with all-new supercharged adventures this fall, Kara and team will come up against a new threat in the form of DC Worldkiller, Reign.
Season 3 Episodes
3x01 Girl of Steel
Kara deals with the loss of Mon-El by focusing all her energy on being Supergirl and the mysterious new threat against National City. Alex confesses a secret to Maggie about their impending nuptials. A citizen of National City has a mysterious connection to Kara, and Lena makes a bold move.
Directing: Jesse Warn · Writing: Robert Rovner, Caitlin Parrish · Starring: Floriana Lima, Calista Flockhart, Adrian Pasdar, David St. Louis
3x02 Triggers
Psi, a thief with psychic powers, attacks National City. Able to immobilize people by tapping into their worst fears, Psi proves a formidable opponent for Supergirl. Meanwhile, James and Lena are at an impasse, and Samantha starts her new job at L-Corp.
Directing: David McWhirter · Writing: Anna Musky-Goldwyn, Gabriel Llanas · Cast: Floriana Lima, Yael Grobglas, Derick Agyemang, Nicole Anthony
3x03 Far From the Tree
Eliza throws Alex and Maggie a wedding shower, which causes Maggie to reach out to her estranged father. Supergirl joins J’onn on a personal mission.
Directing: Dermott Downs · Writing: Derek Simon, Jessica Queller · Cast: Floriana Lima, Carlos Bernard, Dewshane Williams, Louriza Tronco
3x04 The Faithful
Kara investigates a secretive new group whose leader, Thomas Coville, has a mysterious connection to Supergirl. Meanwhile, Samantha feels like she's letting Ruby down, and J'onn confesses an old secret.
Directing: Jesse Warn · Writing: Paula Yoo, Katie Rose Rogers · Cast: Floriana Lima, Sage Brocklebank, David Carzell, Nick Fontaine
3x05 Damage
When multiple children get sick from lead poisoning, Morgan Edge points the finger at Lena and blames her creation of the lead bomb she made to save National City from the Daxamites. While Lena knows she never intended any harm, she fears there may have been a flaw in her design, leaving her responsible. Kara teams up with Samantha to clear Lena’s name, but it turns out to be harder than they thought. Meanwhile, Alex and Maggie make a crucial decision about the future of their relationship.
Directing: Kevin Smith · Writing: Cindy Lichtman, Eric Carrasco · Cast: Floriana Lima, Adrian Pasdar, Bob Frazer, Emy Aneke
3x06 Midvale
Kara and Alex head home to Midvale for a little R&R. While there, Kara recalls a painful memory of a childhood friend's death and how that traumatic experience brought the Danver sisters closer together.
Directing: Rob J. Greenlea · Writing: Caitlin Parrish, Jess Kardos · Starring: Erica Durance, Ivan Mok, Eliana Jones, Carolyn Anderson
3x07 Wake Up
When Winn and the team discover an alien ship has crash landed deep underwater beneath National City, Kara/Supergirl is called in to investigate. Meanwhile, Hank attempts to bond with his father, Myr'nn. Samantha, eager for some understanding of the changes she has been experiencing, looks to her estranged mother, Patricia Arias, for answers.
Directing: Chad Lowe · Writing: Anna Musky-Goldwyn, Gabriel Llanas · Cast: Georgia Hacche, Andres Joseph, Emma Tremblay, Amy Jackson
3x08 Crisis on Earth-X (I)
Barry and Iris’s wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes band together with help from their super friends like Citizen Cold, The Ray, Felicity Smoak, Iris West and Alex Danvers to take on their most formidable villains yet. Earth’s mightiest heroes – Green Arrow, Supergirl, The Flash and White Canary – lead their teams into battle to save the world.The crossover continues on Arrow S06E08 Crisis on Earth-X (II), The Flash S04E08 Crisis on Earth-X (III) and DC's Legends of Tomorrow S03E08 Crisis on Earth-X (IV).
Directing: Larry Teng · Writing: Jessica Queller, Robert Rovner · Cast: Emily Bett Rickards, Danielle Nicolet, Keiynan Lonsdale, Jesse L. Martin
3x09 Reign Mid-Season Finale
Supergirl investigates a mysterious symbol popping up all over National City, tracing its origins back to an ancient prophecy and the mark of the World Killer, Reign. Meanwhile, the tension between Lena and Morgan Edge continues to build, causing James to step in and offer up some protection, and possibly igniting a spark in the process.
Directing: Glen Winter · Writing: Paula Yoo, Caitlin Parrish · Cast: Adrian Pasdar, Emma Tremblay, Amy Jackson, Andre Anthony
3x10 Legion of Superheroes
Struggling to heal from her injuries inflicted by Reign, Supergirl remains in a dreamlike state, unable to be reached. Mon-El recruits one of the Legion members, Brainiac-5, to try to bring her back. Meanwhile, Reign continues her rampage on the city so the DEO teams up with the Legion of Superheroes to try to stop her.
Directing: Jesse Warn · Writing: Derek Simon, Eric Carrasco · Cast: Jesse Rath, Emma Tremblay, Amy Jackson, Anjali Jay
3x11 Fort Rozz
As Reign continues to terrorize the city, Supergirl teams up with Saturn Girl, and the two recruit Supergirl’s former enemies, Livewire and Psi, to form a team for a mission to Fort Rozz to recover a prisoner who has information on how to defeat Reign once and for all. Meanwhile, Alex babysits Ruby.
Directing: Gregory Smith · Writing: Anna Musky-Goldwyn, Gabriel Llanas · Cast: Jesse Rath, Brit Morgan, Yael Grobglas, Sarah Douglas
3x12 For Good
Someone tries to kill Morgan Edge and he barely survives. He accuses Lena of being behind the attempt and vows to destroy her. When Lena fears her hatred for Morgan will take her to the Luthor dark side, Kara steps in to help her friend. Meanwhile, after Sam realizes she’s losing time, she confides in Alex who decides to run some medical tests to see if she can find out what’s going on with her new friend.
Directing: Tawnia McKiernan · Writing: Cindy Lichtman, Alix Sternberg · Cast: Adrian Pasdar, Krys Marshall, Paige Gibbs, David Forts
3x13 Both Sides Now
The DEO captures a second Worldkiller, Purity. Supergirl and Alex use very different methods of interrogation with Purity in the hopes of finding out how to defeat Reign. However, Purity escapes and attacks the city’s subway tunnels. Meanwhile, J’onn, Winn and Mon-El band together to fix the Legion ship.
Directing: Jesse Warn · Writing: Paula Yoo, Jessica Queller · Starring: Herbert Duncanson, Andrew Nadanyi, Krys Marshall, Emma Tremblay
3x14 Schott Through the Heart
When Winn’s father dies, his estranged mother, Mary, reappears trying to reconnect and to explain why she abandoned him all those years ago. Winn is too embittered from his rough childhood to forgive her but when a copycat Toyman attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of Myr'nn’s recent behavior.
Directing: Glen Winter · Writing: Caitlin Parrish, Derek Simon · Starring: Brooke Smith, Gaalen Engen, Laurie Metcalf, Carl Lumbly
3x15 In Search of Lost Time
Myr'nn inadvertently causes psychic disturbances at the DEO; Supergirl must work with J'onn to contain the chaos; Mon-El begins training Kara in fighting techniques he's learned in the future.
Directing: Andi Armaganian · Writing: Katie Rose Rogers, Nicki Holcomb · Starring: Laurie Metcalf, Rochelle Okoye, Glenn Ennis, Krys Marshall
3x16 Of Two Minds
Supergirl and Imra have different ideas on how to stop the third Worldkiller, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction.
Directing: Alexandra La Roche · Writing: Anna Musky-Goldwyn, Gabriel Llanas · Cast: Jesse Rath, Taylor Hastings, Laurie Murdoch, Jennifer Tong
3x17 Trinity
Still reeling after learning about Lena’s secret, Supergirl asks Guardian for a favor that could alter his relationship with Lena forever. Meanwhile, with all three Worldkillers united, Supergirl and the team brace for an epic battle.
Directing: Erica Weiss, Caitlin Parrish · Writing: Derek Simon, Caitlin Parrish · Cast: Jesse Rath, Krys Marshall, Yuvraj Kalsi, Amy Jackson
3x18 Shelter from the Storm
When Reign starts hunting Ruby, Supergirl and Alex work together to keep her safe. Supergirl and J'onn look to Sam’s mother for advice on how to stop Reign and come away with some shocking news.
Directing: Antonio Negret · Writing: Lindsay Gelfand, Allison Weintraub · Cast: Jesse Rath, Cynthia Stevenson, Nesta Cooper, Emma Tremblay
3x19 The Fanatical
When Tanya, a disciple of Coville's, escapes from what's left of his cult, she gives Kara and James a journal that could hold the key to saving Sam. Someone learns Guardian's identity and threatens to expose James if he doesn't do what they ask. James contemplates what it means to be a black vigilante without a mask in America.
Directing: Mairzee Almas · Writing: Paula Yoo, Eric Carrasco · Cast: Sofia Vassilieva, Nesta Cooper, Emma Tremblay, Carl Lumbly
3x20 Dark Side of the Moon
Supergirl is stunned to discover that a part of Krypton survived. Meanwhile, Alex is attacked while out with Ruby, and Lena considers how far she will go to keep Reign contained.
Directing: Hanelle M. Culpepper · Writing: Derek Simon, Katie Rose Rogers · Starring: David Chisum, Tim Russ, Emma Tremblay, Erica Durance
3x21 Not Kansas
Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City.
Directing: Dermott Downs · Writing: Anna Musky-Goldwyn, Gabriel Llanas · Cast: Michael Reilly Burke, Bradley White, Emma Tremblay, Esmé Bianco
3x22 Make It Reign
Supergirl learns the true depth of Selena's nefarious plans for Earth. Supergirl, Mon-El and Alura must devise a plan to stop her before Selena gets to Earth. J'onn prepares to say goodbye to his father.
Directing: Armen V. Kevorkian · Writing: Cindy Lichtman, Ray Utarnachitt · Cast: Emma Tremblay, Esmé Bianco, Erica Durance, Anjali Jay
3x23 Battles Lost and Won Season Finale
Supergirl and team take on Selena in an epic battle for Earth.
Directing: Jesse Warn · Writing: Jessica Queller, Robert Rovner · Cast: Jesse Rath, Emma Tremblay, Amy Jackson, Erica Durance
Season 3 Cast
Odette AnnableSamantha Arias / Reign23 episodes
Emma TremblayRuby Arias15 episodes
Carl LumblyMyr'nn J'onzz11 episodes
Anjali JaySelena10 episodes
Jesse RathQuerl 'Brainy' Dox / Brainiac-56 episodes
Krys MarshallJulia Freeman / Purity6 episodes
Andrea BrooksEve Tessmacher6 episodes
Adrian PasdarMorgan Edge4 episodes
Angela ZhouDr. Grace Parker / Pestilence3 episodes
Curtis LumDemos3 episodes
Yael GrobglasGayle Marsh / Psi2 episodesAll Seasons
Season 12015 · 20 ep. · ★ 6.9
Season 22016 · 22 ep. · ★ 7.1
Season 42018 · 22 ep. · ★ 6.6
Season 52019 · 19 ep. · ★ 6.1
Season 62021 · 20 ep. · ★ 5.5Where to Watch Season 3 of Supergirl
It is currently not available on any streaming platform in Spain.
Frequently Asked Questions
How many episodes does Supergirl Season 3 have?
Supergirl Season 3 has 23 episodes.
When Did Supergirl Season 3 Premiere?
Aired October 9, 2017.
Where to Watch Supergirl Season 3
It is not currently available on any subscription platform in Spain.
What is the best episode of Season 3?
According to the TMDB audience score, 3x06, "Midvale," with a 7.9.