The billionaire-to-be celebrated her milestone age by blessing the world with more pics of precious BB angel Stormi.
"Bringing in my birthday tonight with my most special gift. What was life before you, Stormi. I love you my little angel," she wrote.
We're not ugly crying, you are.
Kylizzle also celebrated the big 2-1 by launching a birthday-themed Kylie Cosmetics collection.
"I can't believe I'm about to turn 21," she said.
"I also can't wait to share this collection with you guys. It's definitely the most personal collection I've done.
"So I hope you guys love it. My birthday collections are super special to me because the first collection I ever did was for my 19th birthday.
"So this is gonna be my third annual. My birthdays are what sort of set off collections for me."
The new range will be available from her site KylieCosmetics.com!