"Happy Birthday my sweet girl! The last 6 years have been the best of my life raising you and seeing you grow up," Kim, 38, wrote on Instagram alongside a slideshow filled with photos of the two of them. "Mommy loves you forever and beyond!"
The makeup mogul's post was filled with comments from fans and celeb friends, including Kimora Lee Simons, Jen Atkins and Mario Dedivanovic, wishing North a happy birthday.
The birthday girl also got some love from grandma Kris Jenner, who shared an adorable post dedicated to the mini fashionista.
"Happy Birthday to my little Angel Northie!!!! What a bright light you are and such a blessing to our family!!" Jenner's message began. "Your magic and sunshine lights up every room and I adore how creative and smart you are. You are so kind and loving to everyone you know and have a beautiful heart and soul."
"I love you so much precious North and it is a pleasure and a privilege to be your Grandmother. I love you ❤️ Lovey xo #HappyBirthdayNorth," she concluded.