AceShowbiz - Singer Yoko Ono posted a photo of herself as a little girl with her mum Isoko on her website, writing, "This is a tribute to you and all mothers of the world from each of your children. We love you!"

Meanwhile, rapper P. Diddy took to his Twitter page to write, "Thank God for Mothers! - Happy Mother's Day!", while singer Sean Kingston added, "Happy Mother's Day!... Salute to all my mothers out there!... Esp (especially) the single ones... I know them 9 months wasn't easy (sic) haha."

Twilight hunk Kellan Lutz posted, "Happy Mother's Day to all you amazing moms! Without you none of us would be here" and Poison star Bret Michaels added, "On behalf of everyone at Michaels Entertainment Group, we'd like to wish a rockin' Happy Mother's Day to all!"

"Bring It On" star Eliza Dushku "Tweeted", "Happy Mother's Day!! To some of my favorite people on the planet - Mommas, feel the love we appreciate & honor you" and Kirstie Alley wrote, "Happy Mother's day!... all u (sic) mothers take a bow!"

Singer Keri Hilson told her Twitter followers, "Being a good mother is one of the hardest jobs in the world... and they make it look so easy. Happy Mother's Day! I love you, Mom!"

And former Eurythmics star Annie Lennox encouraged fans to get charitable on Mother's Day by making a donation to Mothers2mothers, a charity fighting to prevent mother-to-child transmission of HIV.