Though they were wildly different shows, The Vampire Diaries and Smallville shared a surprising number of cast members. Riding the wave of vampire hysteria in the late 2000s, The Vampire Diaries began airing in 2009 and ran for an impressive eight seasons, and even had two spin-offs in the form of The Originals and Legacies. The series was a blend of romance, horror, and fantasy, which opened the door for a host of unique storylines involving witchcraft, werewolves, and vampires. The show's roster of performers often included up-and-coming stars, and The Vampire Diaries was the launching pad for notable names like Ian Somerhalder and Nina Dobrev.

https://screenrant.com/vampire-diaries-actors-roles-smallville-characters/