With the tight trousers she wore a black Kardashian Kollection jacket featuring her last name and the numbers "03" on it.
"Represent #KKollection," she captioned the photo along with a link to the jacket's product page.
"Happy birthday to my sister, spirit animal, partner in crime and best friend! @kyliejenner you constantly amaze me with your wisdom, maturity, sensitive soul, confidence.... I could go on for hours and hours," she captioned the photo. "You and all of my siblings have given me enough love to last me lifetime after lifetime. I wish you and incredible birthday and I'm so sad I'm not with you today. This only means we get to celebrate your birthday when I'm back."
In addition to her shout-out to Kylie, Khloe also continued to support her brother Rob Kardashian, who has been going through a difficult time.
"I'll never let you carry more than you can hold my sweet brother. Almost home kiddo!" she captioned a photo with her brother on Aug. 8.