The reality TV star turned 16 years old on Saturday (10 August) and was inundated with special birthday wishes from the likes of Kendall, Khloe, Kourtney and Kim.
Khloe - who has previously been referred to as Kylie and Kendall's "second mum" - sent more than one heartfelt message to her younger sibling and remarked that the two share a "weirdness" no-one else can relate to.
She wrote: "Happy birthday to my sweet sweet @kyliejenner. No one could ever understand the bond we have and I love that! We understand our weirdness and that's love man!"
Meanwhile, Kendall posted a montage of childhood and recent snaps of herself and Kylie on Instagram, along with the caption: "Happy birthday to my crazy, beautiful, wild little sister @kyliejenner !! Can't believe you're turning 16! I love you and don't know what I would do without you! have an amazing day! lets party! #woohoo #sweet16 #birthdayb*tch!!!"
The family treated Kris and Bruce's youngest daughter to a lavish meal at Nobu restaurant in Malibu, where she was apparently joined by a number of pals, including Will Smith's son Jaden.
And it wouldn't be a party without a cake and some embarrassing 'Happy Birthday' singing!
Khloe, 29, posted a cute snap of Kylie being greeted by her giant cream cake, which was covered in frosting and colourful candles, and showed the 16-year-old dressed smartly for the occasion in a black blazer.
Not at the meal however was sister Kim, who still hasn't made a public appearance since giving birth to her first child, North West, in June.
Although the new mum wasn't in attendance, she made sure to send Kylie some sweet 16 love and uploaded her own collage of pictures that showed herself posing with her youngest sibling throughout the years.
Kim also wrote: "Happy Birthday to my baby sis @kyliejenner !!!! Can't believe you're 16! I love you so much!"
After the celebrations were over, Kylie thanked her friends, family and fans for their messages and admitted that she'd had a great time.
"Love everyone who called and saw me at midnight! Got the best friends & family!" she tweeted.
"Thank you to everyone for the bday wishes and making yesterday so special! Blessed!"
"Honestly had the most amazing night".
How did you celebrate your sweet 16? Let us know below, as the best comment from across the website each week wins £50!