Yesterday was Demi Lovato's 20^th birthday, and fans from all over the world sent her sweet messages to celebrate.

Demi also got lots of messages from friends and family, of course! Miley Cyrus and One Direction's Niall Horan both tweeted nice messages to their friend:

Miley: “@ddlovato happy birthday beautiful! I'm sending you lots of x's if not wasting time on o's. =] have the best day everrrr xxxx.”

Niall: “@ddlovato happy birthday honey! Have a lovely day! See ya soon.”

Aww, that was so nice of her friends! Demi tweeted both of them back, responding “@MileyCyrus thank you so much lady...miss you TONS...love you” and “@NiallOfficial thank you sweet stuff! :)”

Demi also got messages from Nick and Joe Jonas, Bella Thorne, Kim and Khloe Kardashian, Simon Cowell, Glee's Kevin McHale, and Big Time Rush's Logan Henderson.

Sources: Anything Disney, Ocean Up