The pair tied the knot in a romantic ceremony in the Santa Monica Mountains, California, on the weekend.
Nikki, 26, wore an ethereal long-sleeve, backless lace dress while Ian, 36, donned a white suit with a cornflower blue tie.
Ian took to Twitter to address the big day, posting: “most beautiful morning ever…”
The elegant wedding had a rustic feel, with guests dining out in a field beside a barn, with fairy lights strung around to add to the festival atmosphere.
The happy couple’s relationship has progressed at record pace after they began dating in July last year – they only began dating in July last year.
Ian previously dated his former co-star Nina Dobrev for three years while Nikki was married to musician Paul MacDonald. Their divorce only came through in January and shortly after it was revealed Nikki and Ian were engaged.
Despite the short courtship, Ian’s co-star Kat Graham has called the couple “soul mates”.
Kat said: “I haven’t met two people that were more of soul mates than those guys. They are so absolutely amazing. Everyone loves them, and I really can’t imagine him with anyone else.”
Kat was amongst the star-studded line-up of guests who also included Glee’s Lea Michele and her boyfriend Matthew Paetz.
Nikki herself has previously gushed about her new husband too: “He’s quite possibly the most amazing man that’s ever walked the planet, it’s crazy. I’m so lucky, I love him.”
Wishing the happy couple many congratulations during this exciting time!