The Best Episodes of Supergirl
Last Updated: Jun 2, 2019
As Superman’s cousin, Kara Danvers (aka Supergirl) balances her work as a reporter for CatCo Worldwide Media with her work for the Department of Extra-Normal Operations (DEO), a super-secret government organization whose mission is to keep National City – and the Earth – safe from sinister threats..
#1 - Worlds Finest
Season 1 - Episode 18
Kara gains a new ally when the lightning-fast superhero The Flash suddenly appears from an alternate universe and helps Kara battle Siobhan, aka Silver Banshee, and Livewire in exchange for her help in finding a way to return him home.
8.18 
#2 - Crisis on Earth-X (1)
Season 3 - Episode 8
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. Part 1 - Supergirl - S03E08 Part 2 - Arrow - S06E08 Part 3 - The Flash - S04E08 Part 4 - DC's Legends of Tomorrow - S03E08
8.06 
#3 - Nevertheless, She Persisted
Season 2 - Episode 22
Supergirl challenges Rhea to battle to save National City. Meanwhile, Superman returns and Cat Grant offers Supergirl some sage advice.
8.02 
#4 - Reign
Season 3 - Episode 9
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.
7.99 
#5 - Elseworlds (3)
Season 4 - Episode 9
Third and last part of the crossover event with The Flash and Arrow.
7.97 
#6 - Falling
Season 1 - Episode 16
Kara turns on her friends and the citizens of National City after being exposed to Red Kryptonite makes her malicious and dangerous. Also, Cat appears on THE TALK to discuss Supergirl.
7.90 
#7 - Better Angels
Season 1 - Episode 20
Supergirl is forced to do battle with an unexpected foe and must risk everything – including her life – to prevent Non and Indigo from destroying every person on the planet.
7.87 
#8 - Welcome to Earth
Season 2 - Episode 3
An attack is made on the President as hot-button, alien vs. human rights issues heat up in National City. Supergirl and the DEO are assigned to protect the President and bring in the responsible party. Alex teams up with Detective Maggie Sawyer to investigate the case while Kara searches for a recently escaped Mon-El, who she fears may be the alien behind the assault.
7.87 
#9 - Resist
Season 2 - Episode 21
The Daxamites launch a full invasion of National City, killing and arresting civilians. They also attack the DEO, but Alex and Winn manage to escape. Mon-El learns that he has to marry Lena in order to unite the people of Earth with Daxam.
7.84 
#10 - The Adventures of Supergirl
Season 2 - Episode 1
When a new threat emerges in National City, Kara/Supergirl teams up with her cousin, Clark Kent/Superman, to stop it. Kara is thrilled to have family in town but it leaves Alex feeling a bit left out. Meanwhile, Hank and Supergirl are stunned by the pod that came crashing to Earth.
7.83 
#11 - The Last Children of Krypton
Season 2 - Episode 2
CADMUS attacks National City with a Kryptonite-powered villain who ends up seriously hurting Supergirl. Superman blames Hank because the Kryptonite was stolen from the DEO. Meanwhile, Kara’s first day at her new job doesn’t go as planned after she meets her new boss, Snapper Carr.
7.83 
#12 - All About Eve
Season 4 - Episode 17
Supergirl must deal with the destructive aftermath of Lex's nefarious plans. Shocked at what Lex has created, Supergirl faces her biggest challenge yet.
7.82 
#13 - Hostile Takeover
Season 1 - Episode 8
Kara goes toe-to-toe with Astra when her aunt challenges Kara’s beliefs about her mother. Also, Cat is threatened with being removed as the CEO of CatCo after a hacker exposes her private and damaging emails.
7.82 
#14 - The House of L
Season 4 - Episode 16
In the wake of Lex Luthor's return, the show flashes back to what he's been doing for the last two years and how his secret machinations and plans have affected Supergirl and Lena.
7.81 
#15 - Battles Lost and Won
Season 3 - Episode 23
Supergirl and team take on Serena in an epic battle for Earth.
7.80 
#16 - Manhunter
Season 1 - Episode 17
J’onn J’onzz reveals the details of meeting Kara and Alex’s father, Dr. Jeremiah Danvers, and assuming Hank Henshaw’s identity. Also, Kara debates trusting someone new with her secret identity and Siobhan plots against Kara.
7.79 
#17 - O Brother, Where Art Thou?
Season 4 - Episode 15
Secretly furloughed from prison due to failing health, Lex Luthor visits his sister, Lena, to seek her help finding a cure. Savvy as ever, Lena is suspicious of Lex's motives but when she’s faced with a life and death situation, she must decide how she truly feels about her brother. Meanwhile, Supergirl and J'onn face off against Manchester Black. James' sister Kelly comes to town.
7.78 
#18 - Medusa (1)
Season 2 - Episode 8
Eliza comes to town to celebrate Thanksgiving with her daughters. Alex decides it’s time to come out to her mother; Kara is shocked when Eliza suggests Mon-El has feelings for her, and Winn and James consider telling Kara the truth about the Guardian. Meanwhile, CADMUS unleashes a virus that instantly kills any alien in the vicinity so Kara enlists an unexpected ally – Lena Luthor. The epic superhero crossover kicks off tonight when Barry Allen and Cisco Ramon seek Kara’s help with an alien invasion on their Earth. Part 1 - Supergirl - S02E08 Part 2 - The Flash - S03E08 Part 3 - Arrow - S05E08 Part 4 - DC's Legends of Tomorrow - S02E07
7.77 
#19 - Survivors
Season 2 - Episode 4
When Kara and Alex investigate the murder of an unregistered alien, the trail leads to an alien fight club run by Roulette, the ringmaster who commands aliens to fight in mortal combat for the entertainment of rich humans. While trying to stop the fighting, Supergirl and Martian Manhunter find themselves up against a surprising opponent. Meanwhile, Hank is thrilled to have found another Martian and tries to get to know M'Gann better. Supergirl takes Mon-El under her wing and begins to train him.
7.77 
#20 - Bunker Hill
Season 4 - Episode 8
Nia has a powerful dream about Agent Liberty but refuses to look at it as a prophetic dream, Kara and Brainy try to persuade Nia to embrace her destiny, and Manchester Black pays Ben Lockwood a menacing visit.
7.76 
#21 - Girl of Steel
Season 3 - Episode 1
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.
7.76 
#22 - The Darkest Place
Season 2 - Episode 7
While Guardian tries to clear his name after being accused of a murder committed by another vigilante, Supergirl heads out on a solo mission to rescue Mon-El who has been captured by CADMUS. While fighting to free Mon-El, Supergirl comes face to face with Cyborg Superman.
7.76 
#23 - Red Dawn
Season 4 - Episode 21
Kara comes face to face with Red Daughter and the two engage in an epic battle. Determined to find a way to extract the Harun-El, Lena turns to an unlikely source for help – Lillian Luthor. Meanwhile, Alex realizes she’s missing parts of her memory, and Brainy, Nia and J'onn set out to track down aliens who have been abducted by Lex.
7.75 
#24 - Exodus
Season 2 - Episode 15
As Alex searches for Jeremiah and Kara investigates a series of alien kidnappings, the sisters realize they must break the rules to foil a new Cadmus plot. In an effort to get Snapper Carr to run a story that would help her stop Cadmus, Kara agrees to set up an interview between Snapper and Supergirl.
7.74 
#25 - City of Lost Children
Season 2 - Episode 20
The DEO investigates a Phorian woman who uses her telekinetic powers to cause rampage. James tracks down her son, Marcus, who refuses to speak with anyone but James, who spends time bonding with him. With Rhea's encouragement, Lena completes the matter transporter, which Rhea activates, causing Marcus to nearly destroy the office with his powers.
7.74