The model and reality star got a lot of love on her special day.
"Happy Birthday Kenny!!!! My beautiful girl inside and out... you are such an amazing light in the world and you teach me so much about life each and every day," Kris Jenner wrote on Instagram, alongside a slideshow of photos of the birthday girl from different times throughout her life.
"Thank you for giving me another chapter at motherhood and loving all of us unconditionally," she continued. "I thank God for you each day and I’m beyond humbled He chose me to be your Mommy... you are my everything."
Kris went on to call Jenner her "Angel girl," and praised her for being an "amazing daughter, friend, sister, auntie and travel buddy."
Caitlyn Jenner also shared a sweet birthday message, alongside a photo from their recent Halloween festivities.
"A quarter of a century! You continue to amaze me every year and you make me so proud to be your dad. Happy birthday!!!," Caitlyn captioned the pic.
Meanwhile, Kim Kardashian shared a throwback baby photo, showing an infant Kendall sitting on a teenage Kim's lap.
"My baby Kenny! I was 16 years old here and you weren’t even a year old. I can’t believe you’re 25 years old now," Kim wrote. "I always couldn’t wait to see what you would grow up to be like! LOL you were always my baby Kenny doll! I’m so happy all of our siblings found each other in this lifetime! Happy Birthday to the coolest and prettiest girl I know!"
Khloe Kardashians shared her own slideshow of snapshots from the past few years, and wrote in the caption, "Currently scream singing Happy birthday my sweet Kenny!"
"You are one of my most favorite people!" she wrote. "I love you for who you are and couldn't imagine a life without YOU. If anyone knows you like I do, they know how much of an amazing, kind, quirky, loyal, loving person you are and how much any one would dream to have you in their life."
"Some people aren't as lucky as us - not everyone gets to have a sister and not everyone gets to have a love and bond that all us siblings have with one another," Khloe continued. "We are soulmates. In every lifetime we will find one another because we are destined to. Until time runs out, we will be together in some capacity. I am so lucky to have someone as selfless and loving as you by my side. I love you, I respect you, I value everything that you are."
Kendall herself thanked her family, friends and fans for all the well wishes, and used the attention to once again encourage people to vote.
"Thank you all very much for the birthday wishes already! I just wanted to remind everyone in the US that today is more importantly Election Day! So if you're registered but haven't done so yet - please please vote!!!" Kendall wrote in her Instagram Story. "Your voce is sooo important, and your vote can make a difference up and down the ballot."
The heartfelt birthday messages come shortly after Kendall made headlines for her Halloween-themed b-day bash at Harriet's Rooftop atop 1 Hotel in West Hollywood.
Check out the video below for more on star-studded celebration.