Dobrev's boyfriend, Austin Stowell, was also in attendance, along with her co-star Kat Graham, and celebrity friends Nick Jonas, Hailee Steinfeld, Jessica Szohr, Adam Devine, Chace Crawford, Derek Hough, Julianne Hough and Seth McFarlane.
Guests at the party later took to Instagram to share snaps from the fun soiree.
Before the party, Stowell also took to social media to share a sweet birthday message to his girlfriend.
"I think the Dos Equis guy said it best: 'I don't always post pictures, but when I do, it's of a unicorn.' Happy birthday to my favorite little Yankee fan," he captioned the photo, complete with all the birthday-themed emojis, of course.