Like she did with her remembrance of fellow recent anniversary celebrant "The Devil Wears Prada," Hathaway took to Instagram to mark the occasion, posting a GIF of Mia dancing (during the character's makeover/princess training sessions) alongside a heartfelt message that echoed one of Mia's catchphrases.

"It's been 15 years (say it with me) SHUT UP!!!!!" Hathaway wrote. "To all the fans who have loved Mia, Louie, Lily, Joe, Michael and, of course, Queen Clarisse, thank you from the bottom of my heart!"

The actress also had a message for her "Diaries" director and pal, the late Garry Marshall, who passed away last month at the age of 81.

"And to Garry Marshall, thank you for making me a princess," Hathaway wrote. "I love you always my beloved friend and teacher, and I miss you every day."

Marshall made headlines earlier this year when he said that he and Hathaway were plotting to finally make "Princess Diaries 3," though sadly, those plans never came to fruition. Thankfully, we'll always have the first two films.