Pete Ross is a supporting character in the Superman comic books.
The Pre-Crisis version was a childhood friend of Clark Kent in Smallville. One night when they were camping together, Pete saw Clark change into Superboy to attend to an emergency. Unlike many of Clark's friends, Pete kept his knowledge of the superhero's secret identity to himself, not even telling Clark. Furthermore, Pete resolved to help his friend with his knowledge such as creating distractions to allow Clark to slip away without raising suspicion.
As an adult, widower Pete was established as having had a son, Jonathan (mother unrevealed), who also learned the secret of Superman's dual identity (ACTION COMICS #457). In time, Clark learned of Pete's knowledge.
The Legion of Super-Heroes were aware of Pete's assistance to Clark and made him an honorary member during his teenage years (SUPERBOY #98).
The Post-Crisis version is a far more minor character who eventually married Lana Lang. He and Lana have a son, Clark Ross. The two are presently married, but Lana is seeking a divorce. Pete was Vice-President of the United States under Lex Luthor and briefly served as President following Luthor's impeachment.
In the modern comic book continuity, Pete is not initially aware of Clark's secret. However, the secret was known by the villainous Manchester Black, who informed then-President Luthor of the secret, only later to wipe his memory of it. However, prior to losing the knowledge of Clark's secret, Lex informs Pete that his close friend Clark Kent is in fact Superman. As with the former continuity, Pete has yet to reveal to Clark that he knows the secret.
In the television series Smallville, Pete Ross is played by Sam Jones III . He is a childhood friend who learned about Clark's abilities, which Clark admitted to him after Pete stumbled upon his spaceship during an episode from the second season entitled "Duplicity."