Popsugar Celebrity Kylie Jenner Kylie Jenner's 21st Birthday Photos Kylie Jenner Turned 21, and You Can Bet There Was Plenty of "Birthday Behaviour" 11 August 2018 by Tori Crowther First Published: 10 August 2018 View On One Page Photo 4 of 18 ADVERTISEMENT () Start Slideshow BIRTHDAY BEHAVIOR! WERE ALL TURNING 21!! A post shared by Kylie (@kyliejenner) on Aug 9, 2018 at 10:48pm PDT Share This Link Copy ← Use Arrow Keys → 4 Previous Next Start Slideshow Kylie JennerKendall JennerCelebrity BirthdaysKourtney KardashianKris JennerKhloe KardashianKim Kardashian