Supergirl Season Four

Main Characters

 * Melissa Benoist as Kara Danvers / Kara Zor-El / Supergirl
 * Mehcad Brooks as James Olsen / Guardian
 * Chyler Leigh as Alex Danvers
 * Katie McGrath as Lena Luthor
 * Cody Christian as Connor Kent /Kon-El/ Superboy
 * Sam Witwer as Ben Lockwood / Agent Liberty
 * Nicole Maines as Nia Nal / Dreamer
 * David Harewood as J'onn J'onzz / Martian Manhunter

Recurring
Guest
 * Rhona Mitra as Mercy Grave
 * Jesse Rath as Querl "Brainy" Dox / Brainiac
 * Brenda Strong as Lillian Luthor
 * April Parker Jones as Colonel Lauren Haley
 * Tyler Hoechlin as Kal-El / Clark Kent / Superman
 * Elizabeth Tulloch as Lois Lane[
 * Robert Baker as Otis Graves
 * Anthony Konechny as Raymond Jensen / Parasite
 * Andrea Brooks as Eve Teschmacher
 * Bruce Boxleitner as President Baker
 * David Ajala as Manchester Black
 * Jeremy Jordan as Winslow "Winn" Schott, Jr.
 * Jon Cryer as Lex Luthor
 * Xander Berkeley as Peter Lockwood
 * Sarah Smyth as Lydia Lockwood
 * Graham Verchere as George Lockwood
 * Azie Tesfai as Kelly Olsen
 * Hannah James as Maeve Nal

Confirmed new characters

 * Conner Kent/ Kon-el :Is a Clone created by Cadmus Labs, he is carrying the DNA of Superman and Lex Luthor ,he joins Kara in opening to become a superhero
 * Lex Luthor: He will shake things up in National City and go toe to toe with not only Supergirl, but his sister Lena Luthor.
 * Kelly Olsen: Kelly is an intelligent and insightful woman who spent time in the military in order to pay for medical school. She's recently discharged from the military and is currently finishing her training as a psychiatrist. She's got a large heart and cares deeply about others.[2]
 * Pamela Ferrer/Menagerie: A member of Manchester Black’s “Elite,” Menagerie is a jewel thief who doesn’t mind hurting people.[3]
 * Quentin: A wide-eyed government attaché who is grateful when Supergirl saves his life. However, when he shows his true colors by attending an anti-alien rally, Supergirl aims to prove to Quentin that not all aliens are bad.[8]
 * The Hat: A young Japanese man who gains the ability to be invulnerable and breathe fire after being merged with a demon, with his hat serving as his primary condui