But who did he play in the long-running ensemble drama?
Another impetuous bad boy, of course! Ian turned heads in the role of Boone Carlyle, the son of a wealthy family who, along with step-sister/love interest Shannon Carlyle, ends up on the doomed Oceanic Flight 815.
One of many central characters on Lost and a noted fan favorite, viewers were shocked when Boone met his demise in Episode 20 of Season 1, making him the first character to be killed off in the series. After finding an abandoned aircraft on the island with a working radio, he attempts to call for help but ends up crashing in the plane and dies from internal injuries.
Post-death, Boone appeared in three additional episodes of Lost, including the season finale. IGNrated his departure from the series as the fourth most critical death on the show.
Ian himself doesn’t deny that Booneis his most recognizable role to date. His Twitter profile even reads, “Dead guy on LOST now undead on The Vampire Diaries.”
We'll bet he's just been dying to share that clever turn of phrase.