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The Best Episodes of Supergirl Season 3

Every episode of Supergirl Season 3 ranked from best to worst. Discover the Best Episodes of Supergirl Season 3!

Binge this in 16h 6m•Peaking at 8.8/10

Twenty-four-year-old Kara Zor-El, who was taken in by the Danvers family when she was 13 after being sent away from Krypton, must learn to embrace her powers after previously hiding them. The Danvers teach her

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Episode Rankings

  1. #1 Fan Favorite
    Supergirl Season 3 Episode 8 - Crisis on Earth-X (I)
    8.8/10(3985 votes)

    S3:E8

    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).

    Director:Larry Teng
    Writer:Unknown

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  2. Supergirl Season 3 Episode 9 - Reign
    8.5/10(2303 votes)

    S3:E9

    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.

    Director:Glen Winter
    Writers:Paula Yoo, Caitlin Parrish

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  3. Supergirl Season 3 Episode 6 - Midvale
    8.1/10(2373 votes)

    S3:E6

    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.

    Director:Rob J. Greenlea
    Writers:Caitlin Parrish, Jess Kardos

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  4. Supergirl Season 3 Episode 10 - Legion of Superheroes
    7.7/10(1846 votes)

    S3:E10

    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.

    Director:Jesse Warn
    Writers:Derek Simon, Eric Carrasco

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  5. Supergirl Season 3 Episode 1 - Girl of Steel
    7.6/10(2313 votes)

    S3:E1

    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.

    Director:Jesse Warn
    Writer:Unknown

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  6. Supergirl Season 3 Episode 7 - Wake Up
    7.6/10(1962 votes)

    S3:E7

    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.

    Director:Chad Lowe
    Writers:Anna Musky-Goldwyn, Gabriel Llanas

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  7. Supergirl Season 3 Episode 11 - Fort Rozz
    7.5/10(1776 votes)

    S3:E11

    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.

    Director:Gregory Smith
    Writers:Anna Musky-Goldwyn, Gabriel Llanas

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  8. Supergirl Season 3 Episode 15 - In Search of Lost Time
    7.5/10(1661 votes)

    S3:E15

    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.

    Director:Andi Armaganian
    Writer:Unknown

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  9. Supergirl Season 3 Episode 17 - Trinity
    7.5/10(1628 votes)

    S3:E17

    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.

    Directors:Erica Weiss, Caitlin Parrish
    Writer:Unknown

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  10. Supergirl Season 3 Episode 18 - Shelter from the Storm
    7.5/10(1560 votes)

    S3:E18

    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.

    Director:Antonio Negret
    Writer:Unknown

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  11. Supergirl Season 3 Episode 23 - Battles Lost and Won
    7.5/10(1614 votes)

    S3:E23

    Supergirl and team take on Selena in an epic battle for Earth.

    Director:Jesse Warn
    Writers:Jessica Queller, Robert Rovner

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  12. Supergirl Season 3 Episode 4 - The Faithful
    7.4/10(1928 votes)

    S3:E4

    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.

    Director:Jesse Warn
    Writers:Paula Yoo, Katie Rose Rogers

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  13. Supergirl Season 3 Episode 5 - Damage
    7.4/10(1967 votes)

    S3:E5

    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.

    Director:Kevin Smith
    Writers:Cindy Lichtman, Eric Carrasco

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  14. Supergirl Season 3 Episode 16 - Of Two Minds
    7.4/10(1604 votes)

    S3:E16

    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.

    Director:Alexandra La Roche
    Writers:Anna Musky-Goldwyn, Gabriel Llanas

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  15. Supergirl Season 3 Episode 20 - Dark Side of the Moon
    7.3/10(1587 votes)

    S3:E20

    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.

    Director:Hanelle M. Culpepper
    Writers:Derek Simon, Katie Rose Rogers

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  16. Supergirl Season 3 Episode 22 - Make It Reign
    7.3/10(1508 votes)

    S3:E22

    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.

    Director:Armen V. Kevorkian
    Writers:Cindy Lichtman, Ray Utarnachitt

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  17. Supergirl Season 3 Episode 2 - Triggers
    7.2/10(2027 votes)

    S3:E2

    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.

    Director:David McWhirter
    Writers:Anna Musky-Goldwyn, Gabriel Llanas

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  18. Supergirl Season 3 Episode 3 - Far From the Tree
    7.2/10(2027 votes)

    S3:E3

    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.

    Director:Dermott Downs
    Writers:Derek Simon, Jessica Queller

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  19. Supergirl Season 3 Episode 12 - For Good
    7.2/10(1765 votes)

    S3:E12

    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.

    Director:Tawnia McKiernan
    Writer:Unknown

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  20. Supergirl Season 3 Episode 13 - Both Sides Now
    7.2/10(1732 votes)

    S3:E13

    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.

    Director:Jesse Warn
    Writers:Paula Yoo, Jessica Queller

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  21. Supergirl Season 3 Episode 14 - Schott Through the Heart
    7.0/10(1691 votes)

    S3:E14

    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.

    Director:Glen Winter
    Writers:Caitlin Parrish, Derek Simon

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  22. Supergirl Season 3 Episode 19 - The Fanatical
    6.9/10(1597 votes)

    S3:E19

    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.

    Director:Mairzee Almas
    Writers:Paula Yoo, Eric Carrasco

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  23. Supergirl Season 3 Episode 21 - Not Kansas
    6.4/10(1810 votes)

    S3:E21

    Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City.

    Director:Dermott Downs
    Writers:Anna Musky-Goldwyn, Gabriel Llanas

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Season 3 Ratings Summary

"Crisis on Earth-X (I)" is the best rated episode of "Supergirl" season 3. It scored 8.8/10 based on 3985 votes. Directed by Larry Teng and written by Unknown, it aired on 11/27/2017. This episode is rated 0.3 points higher than the second-best, "Reign".