The star told fans she was leaving to get on with "next chapter" of her life.

Rumours of her departure began after pictures of her on a group holiday in Georgia were shared on social media by the show's crew, with the hashtag #ninawewillmissyou.

"I want to be the first to tell you that it wasn't just a holiday celebration, it was a goodbye party," she wrote on Instagram.

Dobrev plays Elena Gilbert, a girl who becomes involved with two vampires - Stefan Salvatore and his brother Damon.

"I always knew I wanted Elena's story to be a six season adventure, and within those six years I got the journey of a lifetime.

"I was a human, a vampire, a doppelganger, a crazy immortal, a doppelganger pretending to be human, a human pretending to be a doppelganger.

"I got kidnapped, killed, resurrected, tortured, cursed, body-snatched, was dead and undead, and there's still so much more to come before the season finale in May.

"Elena fell in love not once, but twice, with two epic soulmates, and I myself made some of the best friends I'll ever know and built an extended family I will love forever."

Series seven of the show has been confirmed and will go ahead without Nina - although many fans are confused as to how the show can go on without her character Elena.

In a statement on The Hollywood Reporter, the show's executive producer Julie Plec, who is pictured in many of Nina's holiday photos, described how it was "bittersweet and beautiful" to say goodbye.

"After six-plus years together, the entire cast and crew of The Vampire Diaries has reached a level of closeness that I don't think any of us ever expected," she said.

"Nina is excited to spread her wings, get some rest, travel the world and also take it by storm, and we support her a thousand-fold.

"We will miss Nina and the 400 characters she played, but we look forward to the insane and exciting challenge of continuing to tell stories of our Salvatore Brothers and our much-loved and gifted ensemble, " she added.