There was a Kryptonian Sect in Pre-Crisis continuity called the Wizards of Juru. They operated in secret and were in hiding from the rest of the 'technological' society of Krypton which shunned magic. The only survivor of it was named Thul-Kar, who managed to transport himself into the Phantom Zone before Krypton's destruction in order for the society to survive.
But he was trapped and essentially become a servant to the consciousness of the Phantom Zone called Aethyr (in fact, when he tried to defy him, his face became disfigured).
As far as I know, his first appearance was in the Phantom Zone mini-series and his second (and only other appearance) was DC Presents#97.
But yes, there were Kryptonian Sorcerors
Interesting, as thought that they as a race shunned all magic, and were just science/tech based!
I thought that was why they had a magical weakness, due to them not wanting to study/know about it at all!
Would that mean that one could be a Kryptonian while on earth, as not have a magical weakness then?