"Happy Mother's Day to this wonderful lady who has put up with me for almost 29 years," the 2 Broke Girls star captioned the photo. "Here's I am trying to nap in a gymnastics class. Nothing has changed."
Bravo's Andy Cohen demonstrated where he gets his face-making abilities:
"Happy Mother's Day!!" he wrote.
Justin Timberlake threw it all the way back to… six months ago:
"Throwback to December at the Grizz game with my Mom and her Mom!!," he wrote. "#HappyMothersDay to ALL of the Mommies out there!! You DA REAL MVPs EVERY DAY!!" (What, no shoutout for the newest mama in his life?)
Amy Schumer shared this photo of her and her mom:
"Happy Mother's Day Sita," she wrote.
Lena Dunham posted a photo of her mama back in the day:
"Mama, thank you for watering us like little flowers," she captioned it. "There's nobody fiercer than you."
Molly Sims was such a darling little baby!
"Happy almost #MothersDay to the best Momma around!!" Sims added to this throwback pic.
Sarah Michelle Gellar shared a series of old photos of her and her mom in the countdown to Mother's Day:
"Happy #MothersDay to this lady," Gellar wrote on the pic she shared on Mother's Day. "The woman who taught me all I know. It's important to remember "Not all superheroes wear capes" #Moms - the real #Superheroes"
Pit Bull was once just a pit puppy:
"Happy Mother's Day to all but in my book every day is Mother's Day," Mr. 305 captioned his pic. "Feliz día de las madres."
Tyra Banks posted an amazing throwback pic from early in her career:
"Me and Mama when I was 18. Paris. Backstage at a fashion show," Tyra wrote. "Mama, you're my first and forever love. Happy Mama's Day to you!"
James Franco gave us a look at the woman who raised him and brothers Dave and Tom:
Christie Brinkley posted about her mom, who passed away in 2012:
"My Beautiful Mom , Marjorie Marie, loved her family and life most passionately," Brinkley wrote. "She graced our home and our lives, with laughter and style. I would give anything for just one more hug and warm smile .. So if your moms still with you , fall to your knees, pray for her health, and give her a squeeze."
Uzo Aduba shared a photo of her "#1 fan":
"Happy Mother's Day and a special shout to mine, my greatest support, my "#1 fan" (her words), whom I love with all my everything--my mommy," Aduba added to the pic. "I love you, Mommy. Love, Zozo :-)."
Gigi Hadid has a famous mom - Real Housewife Yolanda Foster -- and so she has an appropriately glamorous throwback photo of the two of them:
"Happy Mother's Day to my best friend @yolandahfoster," she captioned the parasailing pic. "You continue to inspire and teach me every day and I feel so blessed to call you my mamma! I love and appreciate you endlessly!!"
Eva Longoria got a shot of the whole family:
"Happy Mother's Day to the best mama in the world!!!," she wrote. "#Ella I love u mama!!"
Earlier in the week, Willow Smith posted a pic of her and her mom when Willow was still a sapling: