01/09/2014 04:20 pm ET Updated Jan 23, 2014

Julianne Hough Shares Sweet Photo Of Nina Dobrev On Her 25th Birthday

Julianne Hough and Nina Dobrev's friendship has made headlines over the past few months as the young stars hit the beach, spent the holidays together and helped one another get over their ex-boyfriends. (Ryan Seacrest and Ian Somerhalder, respectively).

And Thursday (Jan. 9), Hough honored Dobrev by sharing a sweet message and snapshot of her "best friend" on her 25th birthday.

"Happy Birthday my beautiful @ninadobrev," the "Safe Haven" star, 25, wrote on Instagram. "You are kind, smart, adventurous, loving, honest, beautiful, mysterious, free, funny, and so on and so forth..... I am so lucky to call you my best friend! I love you so much... My sister! Happy birthday ya ol' fart!!! :) xoxo."

Other close friends of Dobrev's -- including her ex and "Vampire Diaries" co-star Somerhalder -- posted pictures and messages to celebrate her special day:

Too cute!



Julianne Hough Through The Years