Frederick Walden or also known as Dr. Frederick Walden was an arrogant, indifferent man and Clark Kent's archenemy in Smallville.
He is portrayed by Rob LaBelle.
At the beginning of the series, Walden was not interested in working with Lex Luther, no matter how much he was going to play him, but when he saw them firsthand, his interest was piqued. With that, against his will Walden was forced to work with Lex, because Lex believed that Clark knew more about the markings in the caves than he let on. Dr. Walden doubted that a cave boy could have deciphered the language and continued to object to Clark's presence in the caves.
However later when Clark put his hands on the keys in the identical shaped print in the caves, she then flew and fitted on the opposite side of the wall, Dr. Walden withdrew and also placed it in the slot. However after the explosion of energy that caused a circuit in Walden's cerebral vortex and he was put into a coma and sent to Belle Reve. However after that, Walden recovered and he was able to hear about Kriptonian messages. Walden also gained powers to trigger energy projection and he also found out about Clark and tried to expose his secret and alien origins, in addition Walden informed Lex that he should kill Clark.
After that, Walden got off the medication and soon went after Clark, causing a short circuit in the ambulance first and went to the farm. He later tried to kill Clark using his projectiles, however when trying to destroy Clark, he caused an explosion that ended up killing him.