Here's what they tweeted:
Anushka Sharma: May good health, good luck and happiness ring in your homes through the year. Have a tasty Sadhya! Happy Onam.
Shekhar Kapur: Have a blessed Onam. From the Venkittathevar Shiva Temple. Kottakkal. Happy Onam.
Sridevi: Wish you all a very Happy Onam. May this day bring peace, prosperity and happiness to all.
Hema Malini: Happy Onam to you all. It is Kerala's harvest festival celebrated with joy and happiness.
Anupam Kher: Happy Onam to all. Love, peace and happiness always. Festival of Kerala. Spirit of India.
Vishal Dadlani: Have a Happy Onam, everyone! Mallu friends, please don't feel shy about sending me some sadhya!
Farah Khan Ali: Happy Onam to all celebrating. May you have a prosperous happy day.