7.1/101,818 votes#1 - American Alien
Season 4 Episode 1 - Aired 10/14/2018
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.
Director: Jesse Warn
Writer: N/A
7.2/102,177 votes#2 - Fallout
Season 4 Episode 2 - Aired 10/21/2018
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.
Director: Harry Jierjian
Writer: N/A
7.5/101,777 votes#3 - Man of Steel
Season 4 Episode 3 - Aired 10/28/2018
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.
Director: Jesse Warn
Writer: Derek Simon, Rob Wright
6.9/101,521 votes#4 - Ahimsa
Season 4 Episode 4 - Aired 11/4/2018
When Supergirl needs help, Alex asks Lena and Brainiac to team up. Meanwhile, J’onn questions his decision to quit the DEO. However, after running into Manchester Black, he realizes there are a lot of ways to help his fellow aliens during this tumultuous time.
Director: Armen V. Kevorkian
Writer: N/A
6.7/101,605 votes#5 - Parasite Lost
Season 4 Episode 5 - Aired 11/11/2018
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.
Director: David McWhirter
Writer: Aadrita Mukerji, Maria Maggenti
7.0/101,472 votes#6 - Call to Action
Season 4 Episode 6 - Aired 11/18/2018
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.
Director: Antonio Negret
Writer: Gabriel Llanas, Daniel Beaty
7.2/101,445 votes#7 - Rather the Fallen Angel
Season 4 Episode 7 - Aired 11/25/2018
James falls in deeper with the Children of Liberty in his efforts to meet Agent Liberty. Meanwhile, Supergirl and Manchester Black follow a lead on Agent Liberty’s location, but things take a dark turn. Lena kicks off her first set of trials.
Director: Chad Lowe
Writer: Katie Rose Rogers, Dana Horgan
7.5/101,454 votes#8 - Bunker Hill
Season 4 Episode 8 - Aired 12/2/2018
Nia has a powerful dream about Agent Liberty but refuses to look at it as a prophetic dream and pushes it aside. After noticing something is bothering Nia, Kara enlists Brainy's help, and the two try to persuade Nia to embrace her destiny. Meanwhile, Manchester Black pays Ben Lockwood a menacing visit.
Director: Kevin Smith
Writer: Eric Carrasco, Rob Wright
8.4/102,506 votes#9 - Elseworlds (III)
Season 4 Episode 9 - Aired 12/11/2018
Supergirl, The Flash, Green Arrow and Superman engage in the battle of their lives. The crossover starts on The Flash S05E09 Elseworlds (I) and Arrow S07E09 Elseworlds (II).
Director: Jesse Warn
Writer: N/A
7.4/101,373 votes#10 - Suspicious Minds
Season 4 Episode 10 - Aired 1/20/2019
Colonel Haley is upset after Supergirl responds to a distress call from a Navy ship that turned out to be a deadly alien attack. Colonel Haley reclaims the site as DEO territory and demands that Supergirl step aside. After Supergirl refuses to be told what to do, Haley refocuses her energy on finding out Supergirl's true identity and begins to interrogate all DEO agents, including Alex. Meanwhile, Brainiac-5 tries to persuade Nia to embrace her superpowers but she misinterprets his motives.
Director: Rachel Talalay
Writer: Gabriel Llanas, Maria Maggenti
7.0/101,397 votes#11 - Blood Memory
Season 4 Episode 11 - Aired 1/27/2019
Kara joins Nia on a trip to Nia's hometown to visit her family during the town's annual Harvest Festival. While home, Nia's mother encourages her daughter to embrace her destiny. Meanwhile, Alex deals with a street drug that is turning people violent and giving them temporary superpowers.
Director: Shannon Kohli
Writer: Jessica Queller
7.1/101,377 votes#12 - Menagerie
Season 4 Episode 12 - Aired 2/17/2019
With his P.I. shingle newly hung outside his office, J'onn welcomes new clients. Trying to take her mind off what happened at the DEO, Kara decides to team up with J'onn on his latest assignment, which unfortunately ends up tying directly into Alex's current investigation that involves the villain Menagerie. Meanwhile, Lena shares some news with James, but his reaction isn't what she expected. Nia invites Brainy to her Valentine's Day party.
Director: Stefan Pleszczynski
Writer: N/A
7.4/101,275 votes#13 - What's So Funny About Truth, Justice, and the American Way?
Season 4 Episode 13 - Aired 3/3/2019
Manchester Black breaks out of prison with the help of his new team, The Elite, who are set on punishing the anti-alien forces. Supergirl pulls double duty as she tries to apprehend Manchester Black and his team as well as deal with a shocking new development with Ben Lockwood.
Director: Alexis Ostrander
Writer: Eric Carrasco, Aadrita Mukerji
7.3/101,273 votes#14 - Stand and Deliver
Season 4 Episode 14 - Aired 3/10/2019
Between Ben Lockwood’s new push to stir up the anti-alien movement and the Elite’s desire to target Lockwood and his minions, Supergirl is concerned about the safety of the American people – both human and alien. When Lockwood organizes a rally, the aliens decide to peacefully protest. Brainiac and J’onn join the alien march while Supergirl and Dreamer patrol to keep everyone safe. Meanwhile, James picks up his camera again to cover the march for CatCo, and Hayley assigns Alex a job that clashes with her beliefs. When The Elite and Ben Lockwood stir up trouble at the rally, Supergirl is forced to take a stand.
Director: Andi Armaganian
Writer: Rob Wright, Jess Kardos
8.1/101,483 votes#15 - O Brother, Where Art Thou?
Season 4 Episode 15 - Aired 3/17/2019
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.
Director: Tawnia McKiernan
Writer: Derek Simon, Nicki Holcomb
8.3/101,546 votes#16 - The House of L
Season 4 Episode 16 - Aired 3/24/2019
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.
Director: N/A
Writer: Eric Carrasco, Dana Horgan
7.6/101,294 votes#17 - All About Eve
Season 4 Episode 17 - Aired 3/31/2019
Supergirl must deal with the destructive aftermath of Lex's nefarious plans. Shocked at what Lex has created, Supergirl faces her biggest challenge yet.
Director: Ben Hernandez Bray
Writer: N/A
7.5/101,255 votes#18 - Crime and Punishment
Season 4 Episode 18 - Aired 4/21/2019
Kara and Lena head to Stryker's Island to search for clues on how to defeat Lex. At the prison, Kara tries to befriend a nosy prisoner, Steve, who may have insight into what Lex was doing, while Lena studies an array of puzzles Lex left behind in the hopes of discovering his whereabouts. While there, a prison riot breaks out and Kara must find a way to stop the prisoners without revealing her secret identity as Supergirl. Meanwhile, Kelly encourages James to talk to someone for his PTSD, and Alex faces off against Ben Lockwood after he storms the DEO and acquires some powerful weapons to hunt Supergirl.
Director: Antonio Negret
Writer: N/A
7.3/101,315 votes#19 - American Dreamer
Season 4 Episode 19 - Aired 4/28/2019
As Kara doggedly works as a reporter to clear Supergirl's name, Dreamer picks up the slack as National City's protector, which leads to a showdown with Ben Lockwood. James takes drastic measures to relieve his PTSD.
Director: David Harewood
Writer: N/A
7.4/101,289 votes#20 - Will The Real Miss Tessmacher Please Stand Up?
Season 4 Episode 20 - Aired 5/5/2019
Kara and Lena head to Kaznia to hunt down Lex. However, Eve Tessmacher sets a trap for the duo that could ultimately reveal that Kara is Supergirl. Meanwhile, Alex gets a long-awaited phone call, James practices using his powers, and Ben Lockwood takes a dangerous stand inside the DEO.
Director: Shannon Kohli
Writer: N/A
8.1/101,321 votes#21 - Red Dawn
Season 4 Episode 21 - Aired 5/12/2019
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.
Director: Alexis Ostrander
Writer: N/A
8.2/101,385 votes#22 - The Quest for Peace
Season 4 Episode 22 - Aired 5/19/2019
Lex Luthor descends upon Washington, DC and summons Lena and Lillian Luthor to the White House. Supergirl realizes she has one last chance to stop Lex and turns to the power of the press to help her.
Director: Jesse Warn
Writer: N/A
The Best Episodes of Supergirl Season 4
Every episode of Supergirl Season 4 ranked from best to worst. Discover the Best Episodes of Supergirl Season 4!
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...
Genres:DramaSci-Fi & FantasyAction & Adventure
Season 4 Ratings Summary
"American Alien" is the best rated episode of "Supergirl" season 4. It scored 7.1/10 based on 1818 votes. Directed by Jesse Warn and written by N/A, it aired on 10/14/2018. This episode is rated 0.1 points higher than the second-best, "Fallout".