There are so many good episodes of Supergirl, but which ones really stand out? Do you like "Crisis on Earth-X: Part 1" the best, or is "Falling" your favorite episode of Supergirl? To determine once and for all what the best episodes of Supergirl are, let's rank every Supergirl episode from best to worst.
A DC Comics superhero series, Supergirl premiered on CBS on October 26, 2015, and follows Kara Zor-El as she embraces her powers to become the protector of National City. Supergirl, which is set within the Arrowverse, stars Melissa Benoist as Kara, Mehcad Brooks as James Olsen, Chyler Leigh as Alex Danvers, Jeremy Jordan as Winslow "Winn" Schott Jr., and Calista Flockhart as Cat Grant. Beginning with season 2, Supergirl moved to the CW, joining Arrow and The Flash and becoming part of the CW Arrowverse.
Vote up your favorite episodes of Supergirl, and downvote any bad episodes that you really didn't enjoy, despite how much you love the series as a whole. It can be painful to put one Supergirl episode over the other when there are so many good ones, which is why you can vote on however many episodes you like.
Season 2, Episode 19
Alex is kidnapped and the kidnapper threatens to kill her unless Supergirl releases a notorious criminal from prison. Supergirl and Maggie have always had different approaches to apprehending criminals but this time they must work together to save Alex. Meanwhile, Rhea has an interesting proposal for Lena.
Season 2, Episode 12
After Metallo breaks out of prison and frees Lillian Luthor, the police blame Lena for his escape and arrest her. Despite overwhelming evidence, Kara refuses to believe her friend is guilty and fights to clear Lena’s name. Flashbacks reveal how Lena came to be a Luthor.
Season 2, Episode 9
Kara and Mon-El are transported to another planet, led by Roulette where the downtrodden are sold as slaves. Even worse, Kara & Mon-El don’t have their powers.
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.
Season 2, Episode 15
As Alex searches for Jeremiah, Kara agrees to set up an interview between Snapper Carr and Supergirl to help stop a new Cadmus plot.
Season 2, Episode 6
The Guardian debuts to lend a hand after a parasite alien drains Supergirl of her power. Mon-El considers a less than desirable new career and Alex struggles with a new reality.
Season 2, Episode 5
Supergirl must beat a ruthless new gang who has been armed with dangerous new alien technology. When Cadmus sends a video to the DEO, the team realizes Cadmus is the one staffing the criminals for a secret mission. Meanwhile, Kara gets Mon-El a job as an intern at CatCo, James makes an important decision and Lena invites Kara to attend one of her fundraisers.
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.
The crossover continues on The Flash S03E08 Invasion! (II), Arrow S05E08 Invasion! (III) and DC's Legends of Tomorrow S02E07 Invasion! (IV).
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.
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.
Season 2, Episode 14
When Jeremiah Danvers is rescued from Cadmus, Alex and Kara are thrilled to have their father back. The Danvers arrange a family dinner to celebrate but things go awry when a suspicious Mon-El starts to question Jeremiah about his sudden return.
Season 2, Episode 21
Supergirl grapples with whether or not to obey the President's orders regarding Rhea's latest actions. Meanwhile, Cat Grant returns to National City.
The Martian Chronicles
Season 2, Episode 11
When a White Martian (TERRELL TILFORD) descends on National City to capture M’gann, Supergirl and Hank hide her in the DEO, but he follows by shapeshifting.
Season 2, Episode 16
A new villain comes to National City, putting Supergirl on high alert. Meanwhile, Winn’s girlfriend, Lyra, gets Winn in trouble with the law. Maggie attempts to help Winn but old loyalties get in the way. The Music Meister attacks Supergirl.
The crossover continues on The Flash S03E17 Duet (II).
Season 2, Episode 17
When a large bounty is put out on Supergirl, aliens from near and far attack National City intent on taking out the Woman of Steel. Guest star Lynda Carter returns as the President.
Season 6, Episode 5
Nia and Brainy attempt to save Supergirl from the Phantom Zone by time traveling back to Kara's home in 2009. While determined to secure the item needed to help Supergirl, Brainy is worried about keeping a low profile so as not to alter the future timeline. However, when their ship crashes upon arrival, a young Kara Danvers is the first on the scene. Meanwhile, a young reporter named Cat Grant sets her sights on Midvale as she suspects there is a big story in the small town.
Season 6, Episode 1
As Brainiac lays close to death after trying to stop Lex, Supergirl and team soar in to save him, engaging in an epic battle with Gamemnae. After beating Leviathan, Supergirl turns her attention to Lex who has used the Obsidian platform to brainwash half the world to love him and follow him at all costs, no matter what horrible things he does. Knowing how dangerous this makes her brother, Lena enlists the entire team – Alex, J’onn , Dreamer, Kelly and Brainiac – to help, but Supergirl realizes that the only way to truly stop Lex is to sacrifice herself.
We Can Be Heroes
Season 2, Episode 10
After Livewire seemingly breaks out of prison, Supergirl is intent on recapturing her. After training Mon-El, Supergirl takes him with her when she sees Livewire attack the NCPD but things go awry when Mon-El puts Supergirl before the citizens of National City. Meanwhile, James decides to come clean with Kara and M’Gann, has a psychic attack and collapses into a coma.
City of Lost Children
Season 2, Episode 20
When an alien attacks National City, Supergirl and the DEO learn the alien is a Phorian, an otherwise peaceful race with telekinetic powers. Guardian gets a lead on the Phorian's address but instead of finding the culprit, he finds a very scared boy named Marcus. Marcus will only trust James so it is up to Guardian to stop the attacks on the city. Rhea's plan escalates.
Mr. & Mrs. Mxyzptlk
Season 2, Episode 13
When Mr. Mxyzptlk (PETER GADIOT), a magical imp, shows up on Earth and declares his love for Kara, her rejection causes him to wreak havoc on National City.
Season 5, Episode 19
Supergirl realizes that in order to stop Lex and Leviathan she must work with the one person she never thought she’d trust again – Lena. Nia keeps dreaming about Brainy but struggles with what the dreams are trying to tell her. Meanwhile, Brainy realizes there is only one way to stop Lex.
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.
Season 2, Episode 18
Lena’s ex-boyfriend, Jack Spheer, comes to National City to unveil his big breakthrough in nano-technology, which has the potential to eradicate all diseases. Lena asks Kara to attend Jack’s conference with her for support. When Kara sees Snapper in attendance she’s inspired to tap back into her reporter skills and questions Jack on his discovery, which ultimately leads to a bigger investigation that puts everyone in danger.
Season 6, Episode 3
Supergirl makes a new ally. Lena and Lex battle for control of Luthor Corp.
The Last Children of Krypton
Season 2, Episode 2
Cadmus attacks National City with a kryptonite-powered villain who ends up seriously hurting Supergirl. And Kara meets her new boss, Snapper Carr (IAN GOMEZ).