John Shea decided to leave the series after the first season because he was tired of the strenuous commute from New York City to Los Angeles. He returned for four guest spots during seasons two through four.
Dean Cain was the first actor to audition for the part. Series creator Deborah Joy LeVine initially dismissed him as too young, telling her casting director that they were looking for Superman, not Superboy.
Dean Cain and Teri Hatcher both appeared in Supergirl (2015), where Cain portrayed Jeremiah Danvers, the adoptive father of Kara Zor-El. Hatcher played the mother of Mon-El.
Dean Cain (Clark Kent/Superman) and Teri Hatcher (Lois Lane) are the only actors to appear in all 87 episodes of the series.