This one's for the dads! On Sunday, celebrities such as Michelle Obama [1], Kim Kardashian [2], and Jennifer Lopez [3] celebrated Father's Day [4] with touching Instagram tributes. "Thank you for the way you love our girls—and all the young people in this country, no matter who they are or where they come from," Michelle captioned a photo of Barack Obama with their daughters, Malia and Sasha. "We feel your warmth and generosity today and everyday. Happy Father's Day, Barack!" Prince William and Kate Middleton — who celebrated the Duke of Cambridge's 38th birthday by sharing new portraits [5] on Saturday — posted a touching salute to their respective fathers, Prince Charles and Michael Middleton. "Happy Father's Day!" they wrote. Keep reading to see how more stars are honouring the holiday!