Winn Schott (Jeremy Jordan)
Winn is the son of the villain Toyman. Becoming friends with Kara when working as a programmer at Catco. Media, Winn would go on to help Kara become Supergirl and assisted the D.E.O. on a number of cases before officially joining them.
Mon-El (Chris Wood)
Mon-El is the prince of Daxam, a planet close to Krypton. When Krypton was destroyed Mon-El managed to escape in a Kryptonian pod, crashing on Earth. Initially wanting a normal life he became inspired to become a hero, and even fell in love with Kara.
When Mon-El’s parents attacked Earth with a Daxamite fleet he fought to stop them, before becoming poisoned and forced to leave Earth.
Maggie Sawyer (Floriana Lima)
Alex’s girlfriend and police officer in the National City Police Department’s Science Police, Maggie is used to working with aliens.
She has worked alongside Alex and the D.E.O. on a number of occassions.
Lena Luthor (Katie McGrath)
Adopted sister to Lex Luthor, Lena is the head of L-Corp since Lex was sent to prison.
She is a good friend to Kara, and has helped Supergirl on more than one occasion, though she is unaware that they are the same person.