Entertainment TV Oprah Winfrey Gets Birthday Wishes from Reese Witherspoon, Niecy Nash, Will Smith and More as She Turns 68 "Happy birthday to the most inspiring mentor and friend I could ever ask for!" Reese Witherspoon posted in honor of Oprah Winfrey's birthday By Tristan Balagtas Tristan Balagtas Digital News Writer, PEOPLE People Editorial Guidelines Published on January 29, 2022 06:20 PM Share Tweet Pin Email Trending Videos Photo: Reese Witherspoon/Instagram Happy birthday, Oprah Winfrey! The media mogul celebrated her 68th trip around the sun on Saturday as her famous followers flooded Instagram with loving wishes in honor of the special day. "Happy birthday to the most inspiring mentor and friend I could ever ask for! Thank you for all the Good work you put into this world everyday!" Reese Witherspoon posted on her Instagram Story, along with a candid snapshot of the pals walking arm in arm. The Big Little Lies star continued the birthday celebration with a video of the pair hilariously confirming their friendship. "We are so actually friends," Winfrey said. "We really are friends," Witherspoon, 45, added. Oprah Insisted on Wearing Red Suit to Match Bows Before Car Giveaway – and Gayle King Wasn't a Fan! Witherspoon wrote in the caption: "In honor of the amazing @oprah's birthday, sharing the video that plays rent-free in my head everyday. I ❤️ you, OW!!" Winfrey's pals Niecy Nash, Viola Davis and Will Smith also wished her a happy birthday. "Screaming Happy Birthday Beauty!!!! @oprah love you to the sky! ❤️🎉❤️🎉," wrote Nash, 51, alongside a photo of the duo sharing a laugh. "Happy birthday to our jewel, this icon, beauty.....@Oprah!! Love ya Sis ❤️❤️❤️❤️," Davis, 56, captioned a solo shot of Winfrey from The Hollywood Reporter. Smith, 53, simply gushed on his Instagram Story, "Happy Bday @oprah!!" Oprah Winfrey Threw out Half a Cake to 'Reset' Her Diet for the New Year: 'Goodbye Two-Week Old Cake' 2022 has already proved to be a fresh start for Winfrey. Earlier this month, the Weight Watchers director and spokesperson announced that she was taking control of her health by "resetting" her diet after spending the holidays with friends and family. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. In a video posted to Instagram, she showed herself dumping out an entire half of a cake, while also promoting the wellness program. "Time for a reset. Clearing out the fridge," Winfrey said at the start of the clip. RELATED VIDEO: People Who Inspire: Oprah Winfrey With 12 visitors in her house over the holidays, she joked, "We ate every day like food had just been invented. So, clearing out the fridge. No chance of one last piece of Gayle [King's] delicious Bananas Foster birthday cake." The former talk show host captioned the clip: "If you've been waiting for the right day, the right time, or some kind of sign…this is it. Today is the day." She humorously added, "Goodbye two-week old cake, hello hydration 👋🏾."