The actress, who has been through troubled times of late as her six-year marriage to Ashton Kutcher ended and she sought treatment for exhaustion and stress, has been traveling.
She was in India last week where she was among the 150 guests - said to include Kate Moss, Bob Geldof, Zac Posen and Sarah Ferguson, duchess of York - at a lavish birthday party for supermodel Naomi Campbell's Russian billionaire boyfriend Vladimir Doronin, reports People.com.
Writer Nimisha Tiwari tweeted a photo of Demi at the bash in traditional garb by designer Manish Malhotra.
People says Demi has since jetted to Dubai.
Campbell is among the many noting Demi's special day today, tweeting: "happy birthday Demi , wishing you happiness true love and more success you are an inspiration& Icon 2 us woman all over the world ... Keep that shining glow that I saw in India and amazing Spirit ! love and respect x N."
(Copyright © 2012 USA TODAY)