“Supergirl” Kara’s father Zor-El was played by "Queer As Folk" actor Robert Gant for the first two seasons, but when the character reappeared in the final season, he was played by “Roswell, New Mexico’s" Jason Behr. While no official explanation was given, Gant had appearances in other shows during “Supergirl’s” final season, so he was probably unavailable.