He is of course best-known for playing Damon in the hit TV show The Vampire Diaries, which returns in the US on October 11. Here are the top ten facts that you should know about him.
1. Ian Joseph Somerhalder was born on December 8, 1978 in Covington, Louisiana. He has an older brother and younger sister. Ian's career started at the age of 10 when he started modelling.
2. Since his breakout role in the short-lived Dawson's Creek spin off Young Americans, Ian has been in such films as The Rules of Attraction and had recurring roles in TV shows such as Smallville and Lost. He currently plays the handsome-yet-dark Damon Salvatore in CW's The Vampire Diaries.
3. Ian not only acts, but he also owns a pizza parlour in Idaho with his siblings. In April, he opened a furniture shop called Built of Barnwood with his brother, and they build and sell their own pieces.
4. Campaigner Somerhalder was very vocal in highlighting the problems caused by the 2010 BP oil spill in the Gulf. He spent his summer off from The Vampire Diaries helping with the clean-up and appeared on Larry King's special two-hour telethon Disaster in The Gulf - How You Can Help.
5. Ian also spends a lot of time working with environmental charities. He was recently honoured at the Environmental Media Awards for his contributions from his charity The Ian Somerhalder Foundation.
6. In his spare time, Ian works on screenplays and loves to write. He has said if he did not act he would have chosen a career in writing, advertising or marine biology.
7. Ian is a very sporty person, enjoying yoga, baseball, horse riding, archery, football and cycling.
8. Somerhalder has been in a relationship with his Vampire Diaries co-star Nina Dobrev since 2010. Nina infamously once told Seventeen magazine that she would not date her co-stars.
9. Ian did not graduate from high school because he went to Europe to pursue a modelling career. He has modelled for such companies as Calvin Klein, Dolce & Gabanna, Ralph Lauren, Gucci, Versace and Guess. He doesn't like talking about his modelling career because he doesn't want people to think that he is just "another pretty face".
10. Despite the internet buzzing about Ian being Christian in Fifty Shades of Grey he is definitely not "desperate" to do the role. As he stated on Twitter in June: "I'm not 'desperate' to do anything except relax today."