The reality TV star, who had her third child in December, has been keeping a low profile recently but decided to let her hair down on her 36th birthday - Vegas style!
The gorgeous mummy chose to wear all-black on her special night (18 April) as she partied at 1 OAK Nightclub with partner Scott Disick and friends.
Looking beautiful in a short LBD, Kourtney wore her hair loose and long and showed no signs of the "14 stubborn pounds" she has admitted she wants to lose after giving birth.
In fact, we think Kourtney looks the best she ever has - so sexy, Kourtney!
Husband Scott was one of the first to congratulate long-term girlfriend Kourtney on social media when he posted the message: "Happy birthday my buttery little baby."
Sister Kim said: "Happy Birthday to my big sister @kourtneykardash. You were always there for me to copy everything you did when we were kids and now you are there to teach me everything as an adult! You are the best mum and I'm so happy our kids get to grow up together as if they are siblings! I learn so much from you everyday! I Love you and I'm so proud you are my sister! Don't know what I would do without you!"
Khloe, meanwhile, posted a gushing tribute to her elder sister saying: "Kourt you are the yin to my yang, the Siegfried to my Roy, the Lucy to my Ricky, The Thelma to my Louise, the Wayne to my Garth, the Posh to my David, the sugar to my spice, the icing to my cake.
"I cannot express how much I love you, respect you, admire you… You inspire me every day. I couldn't ask for a better big (little) sister. My life would be meaningless without ALL of you. So with every single birthday I am more and more appreciative that we get to spend another year together only strengthening our bond as soulmates every single one of us."
Mum Kris posted this sweet tribute: "Happy Birthday Kourtney!!!! You are the very first love of my life, my soulmate, my ride or die, my everything. When you were born I realised what true love really is. You are the most amazing Mum I have ever known, the best daughter, friend, sister, and partner and you are loyal to a fault...
"You are the most beautiful person inside and out and I am so blessed and honoured to be your Mum and we are all better because we get to share life with you. Happy Birthday sweet girl I love you more than you will ever know. Mommy xo @kourtneykardash #blessed #love #family#memories #sorryaboutthisbonnet."
Wow, that's a LOT of love for one very lucky birthday girl!
All you need to know about Kourtney Kardashian in just one minute:
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