Sussanne took to Instagram to share a photograph, and wrote: "Forever and always you stay the sunshine in my life. Happy happiest birthday. Smile that smile brightest and you always will spread that light... Limitless. Sacred heart."
Hrithik and Sussanne had got married in 2000 after a prolonged fairy tale love story. The couple has two sons, Hrehaan and Hridhaan. They separated in December 2013 and their divorce was finalised in November 2014.
Son of filmmaker Rakesh Roshan, Hrithik made his debut in 2000 in "Kaho Naa... Pyaar Hai". He was later seen in films like "Fiza", "Kabhi Khushi Kabhie Gham...", "Koi... Mil Gaya", "Krrish", "Krrish 3" "Jodhaa Akbar", "Guzaarish", "Zindagi Na Milegi Dobara", "Agneepath" and "Bang Bang!".
The actor, who was last seen on screen in "Kaabil" last year, is currently prepping for "Super 30", a film on Anand Kumar - a mathematics genius from a modest family in Bihar.
Here's what the celebs have tweeted:
Akshay Kumar: Even though you're already blessed with the best... Best family, friends, neighbours. This year wishing you better than the best! Happy birthday Hrithik.
Sonam Kapoor: Happy birthday Hrithik! Can't believe it's been more than two years since "Dheere Dheere". Time truly flies! Wish you all the love and joy on this special day.
Riteish Deshmukh: Happy Birthday Dear Hrithik Roshan -- have a great one and may you always radiate positivity where ever you go. Big hug.
Vivek Anand Oberoi: Super hero on screen, super buddy in real life... Love you brother! Happy bday! Hrithik Roshan. Happy Birthday Hrithik Roshan.
Shilpa Shetty Kundra: Happiest Birthday to you Hrithik you are such a special soul. Wishing you happiness, success love in abundance and great health above all.
Genelia Deshmukh: Happy Birthday Dear Hrithik. May you have a fabulous year ahead. A little in the day but I absolutely love the HRX stuff you sent us. Thank You.