Eliza and Jeremiah Danvers (Helen Slater & Dean Cain)
Kara’s foster parents, and Alex’s biological parents, the Danvers’ took Kara in when asked to by Superman; the two of them having helped the hero in the past. Jeremiah worked for the D.E.O. under the real Hank Henshaw, and helped to save J’onn J’onzz’s life.
Since then he was kidnapped by Project Cadmus, who want to destroy all aliens, and has been forced to help them.
Cat Grant (Calista Flockheart)
The former C.E.O. of CatCo. Media, Cat worked alongside Clark Kent and Lois Lane at the Daily Planet before moving to National City to launch her own company.
Cat gave Kara her first job, and would go on to coin the name Supergirl in the media before deciding that she needed to leave National City for a while to reconnect with her son.
Clark Kent/Superman (Tyler Hoechlin)
Kara’s cousin, Superman is the son of a Kryptonian scientist who sent his infant son to Earth before the destruction of his home planet. Superman put Kara in the care of the Danvers, and has kept a close eye on her progress as a hero ever since.
He fought alongside Kara during the Daxamite invasion, praising her heroics after the event.
Lillian Luthor/The Doctor (Brenda Strong)
Lillian Luthor, the mother of Lex Luthor, is the head of the anti-alien group Project Cadmus.
Lillian has worked to destroy Supergirl and other aliens, having released a deadly virus, the villain Metallo, and turned Hank Henshaw into Cyborg Superman.
Hank Henshaw/Cyborg Superman (David Harewood)
The original Hank Henshaw was taken in by Project Cadmus and enhanced with cybernetics to become Cyborg Superman.
Working alongside Lillian Luthor, he has made it his mission to destroy all aliens.
President Olivia Marsdin (Lynda Carter)
President of the United States, Marsdin pardoned J’onn for assuming Henshaws identity and appointed him head of the D.E.O., as well as extending an official amnesty to all aliens on Earth.
It was later revealed that Marsdin is secretly an alien shapeshifter, a Durlan, with a plan of its own for the planet and Supergirl, though none of our heroes know this.
Supergirl Season 3 premieres in the UK on Sky on Monday 16th October. Will you be watching?