Kendall and Kylie both used Instagram to post Father's Day messages to their famous dad, who is now known as Kaitlyn.

Kendall posted a sweet photo of her dad, when he was still known as Bruce Jenner, kissing her on the cheek when she was just a little girl. On her photo, the 19 year old model posted "my whole life this soul was my daddy and just because your appearance is different now doesn't mean you were any less of a father to me my entire life. Happy Father's Day to the person who raised me, and taught me everything I know, my hero."

Kylie also posted an adorable family picture of her with her dad, sister Kendal and mom Kris Jenner. She captioned ""Happy Father's Day my little light of sunshine.' You can still call me dad, Kylie. No matter what I'm always going to be your father. That's never going to change.'"

Khloe Kardashian joined her half-sisters in congratulating Bruce, also on Instragram . Referring to her late biological father Robert Kardashian and step dad Bruce, now Caitlyn Jenner, the reality TV star wrote "Thank you Lord for blessing me with not one phenomenal father but I was lucky enough to have two. Happy Father's Day!!!"

The Kardashian-Jenner family has had to adjust to the radical transformation of their father Bruce Jenner, who underwent a transition from male to female this year. Kaitlyn Jenner recently spoke about the dramatic change in an emotional Diane Sawyer interview. The interview was followed by a cover story on Vanity Fair, accompanied by stunning photographs taken by legendary photographer to the stars Anne Leibovitz.

Kim Kardashian, the most famous of the Kardashian-Jenner clan, dedicated Father's Day to three fathers in her life: Robert Kardashian, Caitlyn Jenner and husband and father of her child Kanye West. The star, pregnant with her second child wrote on Instagram: "I'm so lucky to be married to a man who is so in love with his daughter, your bond is so irreplaceable! Thank you for being such a good dad! We love and appreciate you so much! We're so blessed to have you!"

Kim has previously struggled with her fertility and has spoken about how hard it was for her to get pregnant with her first child.