Throughout the day, Kylie's famous family also posted tributes to their beloved beauty guru, who is set to become the youngest self-made billionaire ever this year, according to Forbes.
"Happy 21 st birthday to my baby!!!!!" wrote momager Kris Jenner. "You are my youngest, my beautiful angel, and it has been life’s greatest reward to watch you grow into an amazing young woman who is the most incredible mom to Stormi, sister, business woman, friend and daughter."
"You are truly a special soul and you have the biggest heart and you are so kind and generous and thoughtful to everyone," she continued. "I am so proud of you Kylie, and I thank God he chose me to be your mommy. I love you more than you will every know... mommy xoxo."