Here's what they tweeted:
Sridevi: Wish each one of you all a very Happy Onam. May this occasion bring happiness, prosperity and good luck.
Hema Malini: Wish all those celebrating today - A Very Happy Onam! Have a wonderful day filled with great joy!
Madhur Bhandarkar: May the colours & lights of Onam fill your home with happiness and joy. Happy Onam (sic).
Anupam Kher: Happy ONAM to all. Love, Peace & Happiness Always.:)
Shruti Haasan: Happy Onam everyone!!!
Anushka Sharma: Happy Onam!! Onam brings back memories of eating delicious meals at my friend @snehhamenon house in Bangalore. Yummy yummy!!
Neha Dhupia: Was born n raised in #kerala... N this festival always brought so much joy to our lives... happy #Onam friends...