Season 3 (Supergirl)

The third season of ​​​​​ premiered on October 9, 2017 on The CW and concluded on June 18, 2018. The season consisted of 23 episodes.
==Cast==
===Main cast===
*Melissa Benoist as Kara Danvers/Supergirl, Kara/Overgirl and Red Daughter
*Mehcad Brooks as James Olsen/Guardian and James Olsen's Earth-X doppelgänger
*Chyler Leigh as Dr. Alex Danvers
*Jeremy Jordan as Winn Schott
*Katie McGrath as Lena Luthor
*Odette Annable as Samantha Arias/Reign
*Chris Wood as Mon-El
*David Harewood as Director J'onn J'onzz/Martian Manhunter
===Recurring cast===
*Floriana Lima as Detective Maggie Sawyer
*Erica Durance as Alura Zor-El
*Adrian Pasdar as Morgan Edge
*Emma Tremblay as Ruby Arias
*Sharon Leal as M'gann M'orzz/Miss Martian
*Andrea Brooks as Eve Teschmacher
*Yael Grobglas as Gayle Marsh/Psi
*Helen Slater as Dr. Eliza Danvers
*Carl Lumbly as M'yrnn J'onzz
*Chad Lowe as Thomas Coville
*Anjali Jay as Selena/Fortress of Sanctuary hologram
*Curtis Lum as Demos
*Amy Jackson as Imra Ardeen/Saturn Girl
*Jesse Rath as Querl Dox/Brainiac 5
*Krys Marshall as Julia Freeman/Purity
==Synopsis==
==Episodes==
1 	 	Jesse Warn 	Andrew Kreisberg 	Robert Rovner & Caitlin Parrish 	October 9, 2017
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 Luthor makes a bold move. 	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 Luthor makes a bold move. 	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 Luthor makes a bold move. 	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 Luthor makes a bold move. 	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 Luthor makes a bold move. 	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 Luthor makes a bold move.
2 	 	David McWhirter 	Gabriel Llanas & Anna Musky-Goldwyn 	Gabriel Llanas & Anna Musky-Goldwyn 	October 16, 2017
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 Olsen and Lena Luthor are at an impasse, and Samantha starts her new job at L-Corp. 	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 Olsen and Lena Luthor are at an impasse, and Samantha starts her new job at L-Corp. 	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 Olsen and Lena Luthor are at an impasse, and Samantha starts her new job at L-Corp. 	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 Olsen and Lena Luthor are at an impasse, and Samantha starts her new job at L-Corp. 	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 Olsen and Lena Luthor are at an impasse, and Samantha starts her new job at L-Corp. 	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 Olsen and Lena Luthor are at an impasse, and Samantha starts her new job at L-Corp.
3 	 	Dermott Downs 	Jessica Queller & Derek Simon 	Jessica Queller & Derek Simon 	October 23, 2017
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. 	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. 	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. 	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. 	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. 	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.
4 	 	Jesse Warn 	Paula Yoo & Katie Rose Rogers 	Paula Yoo & Katie Rose Rogers 	October 30, 2017
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. 	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. 	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. 	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. 	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. 	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.
5 	 	Kevin Smith 	Eric Carrasco & Cindy Lichtman 	Eric Carrasco & Cindy Lichtman 	November 6, 2017
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.	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.	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.	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.	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.	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.
6 	 	Rob Greenlea 	Caitlin Parrish & Jess Kardos 	Caitlin Parrish & Jess Kardos 	November 13, 2017
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 Danvers sisters closer together. 	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 Danvers sisters closer together. 	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 Danvers sisters closer together. 	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 Danvers sisters closer together. 	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 Danvers sisters closer together. 	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 Danvers sisters closer together.
7 	 	Chad Lowe 	Gabriel Llanas & Anna Musky-Goldwyn 	Gabriel Llanas & Anna Musky-Goldwyn 	November 20, 2017
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. 	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. 	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. 	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. 	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. 	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.
8 	 	Larry Teng 	Andrew Kreisberg & Marc Guggenheim 	Robert Rovner & Jessica Queller 	November 27, 2017
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. 	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. 	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. 	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. 	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. 	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.
9 	 	Glen Winter 	Paula Yoo & Caitlin Parrish 	Paula Yoo & Caitlin Parrish 	December 4, 2017
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. 	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. 	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. 	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. 	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. 	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.
10 	 	Jesse Warn 	Derek Simon & Eric Carrasco 	Derek Simon & Eric Carrasco 	January 15, 2018
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. 	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. 	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. 	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. 	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. 	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.
11 	 	Gregory Smith 	Gabriel Llanas & Anna Musky-Goldwyn 	Gabriel Llanas & Anna Musky-Goldwyn 	January 22, 2018
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. 	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. 	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. 	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. 	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. 	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.
12 	 	Tawnia McKiernan 	Robert Rovner 	Cindy Lichtman & Alix Sternberg 	January 29, 2018
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. 	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. 	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. 	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. 	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. 	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.
13 	 	Jesse Warn 	Jessica Queller & Paula Yoo 	Jessica Queller & Paula Yoo 	February 5, 2018
The DEO captures a second World killer, 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. 	The DEO captures a second World killer, 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. 	The DEO captures a second World killer, 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. 	The DEO captures a second World killer, 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. 	The DEO captures a second World killer, 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. 	The DEO captures a second World killer, 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.
14 	 	Glen Winter 	Caitlin Parrish & Derek Simon 	Caitlin Parrish & Derek Simon 	April 16, 2018
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 Toymam attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of M'yrnn's recent behavior. 	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 Toymam attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of M'yrnn's recent behavior. 	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 Toymam attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of M'yrnn's recent behavior. 	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 Toymam attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of M'yrnn's recent behavior. 	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 Toymam attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of M'yrnn's recent behavior. 	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 Toymam attacks, the two must work together to stop him. Mon-El tells Kara something important about the Worldkillers, and Alex becomes suspicious of M'yrnn's recent behavior.
15 	 	Andi Armaganian 	Eric Carrasco 	Katie Rose Rogers & Nicki Holcomb 	April 23, 2018
M'yrnn 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. 	M'yrnn 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. 	M'yrnn 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. 	M'yrnn 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. 	M'yrnn 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. 	M'yrnn 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.
16 	 	Alexandra La Roche 	Gabriel Llanas & Anna Musky-Goldwyn 	Gabriel Llanas & Anna Musky-Goldwyn 	April 30, 2018
Supergirl and Imra have different ideas on how to stop the third world killer, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction. 	Supergirl and Imra have different ideas on how to stop the third world killer, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction. 	Supergirl and Imra have different ideas on how to stop the third world killer, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction. 	Supergirl and Imra have different ideas on how to stop the third world killer, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction. 	Supergirl and Imra have different ideas on how to stop the third world killer, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction. 	Supergirl and Imra have different ideas on how to stop the third world killer, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra team up to stop the destruction.
17 	 	Caitlin Parrish & Jesse Warn 	Jessica Queller 	Caitlin Parrish & Derek Simon 	May 7, 2018
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. 	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. 	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. 	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. 	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. 	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.
18 	 	Antonio Negret 	Robert Rovner 	Lindsay Gelfand & Allison Weintraub 	May 14, 2018
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. 	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. 	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. 	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. 	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. 	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.
19 	 	Mairzee Almas 	Paula Yoo & Eric Carrasco 	Paula Yoo & Eric Carrasco 	May 21, 2018
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. 	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. 	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. 	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. 	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. 	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.
20 	 	Hanelle Culpepper 	Derek Simon & Katie Rose Rogers 	Derek Simon & Katie Rose Rogers 	May 28, 2018
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. 	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. 	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. 	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. 	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. 	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.
21 	 	Dermott Downs 	Gabriel Llanas & Anna Musky-Goldwyn 	Gabriel Llanas & Anna Musky-Goldwyn 	June 4, 2018
Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City. 	Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City. 	Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City. 	Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City. 	Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City. 	Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City.
22 	 	Armen V. Kevorkian 	Ray Utarnachitt & Cindy Lichtman 	Ray Utarnachitt & Cindy Lichtman 	June 11, 2018
After learning the true depth of Selena's nefarious plans for Earth, Supergirl, Mon-El and Alura must come up with a plan to stop her. J'onn prepares to say goodbye to his father. 	After learning the true depth of Selena's nefarious plans for Earth, Supergirl, Mon-El and Alura must come up with a plan to stop her. J'onn prepares to say goodbye to his father. 	After learning the true depth of Selena's nefarious plans for Earth, Supergirl, Mon-El and Alura must come up with a plan to stop her. J'onn prepares to say goodbye to his father. 	After learning the true depth of Selena's nefarious plans for Earth, Supergirl, Mon-El and Alura must come up with a plan to stop her. J'onn prepares to say goodbye to his father. 	After learning the true depth of Selena's nefarious plans for Earth, Supergirl, Mon-El and Alura must come up with a plan to stop her. J'onn prepares to say goodbye to his father. 	After learning the true depth of Selena's nefarious plans for Earth, Supergirl, Mon-El and Alura must come up with a plan to stop her. J'onn prepares to say goodbye to his father.
23 	 	Jesse Warn 	Robert Rovner & Jessica Queller 	Robert Rovner & Jessica Queller 	June 18, 2018
Supergirl and team take on Selena in an epic battle for Earth. 	Supergirl and team take on Selena in an epic battle for Earth. 	Supergirl and team take on Selena in an epic battle for Earth. 	Supergirl and team take on Selena in an epic battle for Earth. 	Supergirl and team take on Selena in an epic battle for Earth. 	Supergirl and team take on Selena in an epic battle for Earth.
==Trivia==
*Starting this season, the title card changes to match the theme of the season.
*Season 3 marked the last for regulars Jeremy Jordon and Chris Wood as well as Odette Annable's only season as a regular and the first to feature new co-showrunners Jessica Queller and Robert Rovner. It is also the last season for co-showrunner Andrew Kreisberg. Greg Berlanti stepped in to co-showrun the rest of Season 3 with Queller and Rovner following Kreisberg's firing in November 2017 due to sexual misconduct allegations made towards him.
==Gallery==
===Title cards===
Supergirl season 3 title card.png|Title card
Crisis on Earth-X title card.png|Title card variant from 
===Promotional images===
Supergirl season 3 poster - Flying Solo.png|"Flying Solo"
Reign promotional image.png|First look at Reign.
Supergirl season 3 poster - Mon-El with a Legion ring.png|Mon-El with a Legion ring.
Supergirl season 3 poster - Mon-El in his Legion suit.png|Mon-El in his Legion suit.
Supergirl season 3 poster - Miss Me?.png|"Miss Me?"
Mon-El's new suit promotional image.png|First look at Mon-El's new suit.
===Videos===
Supergirl Season 3 Comic-Con Trailer (HD)
Supergirl Season 3 Inside (HD)
Supergirl Season 3 Producer's Preview (HD)
DCTV Crisis on Earth-X Crossover Teaser - The Flash, Arrow, Supergirl, DC's Legends of Tomorrow (HD)
Supergirl Season 3 "I Got This" Extended Promo (HD)
Supergirl Season 3 "Hero's Journey" Trailer (HD)
Midseason on The CW Trailer (HD)
==References==
fr:Saison 3 (Supergirl)
pl:Sezon 3 (Supergirl)