The supermodel, 24, rang her parent to congratulate her after she exited the competition with singer Nadine Coyle in the final days of the show.
The supportive call was revealed in Thursday (December 12) night's I'm A Celebrity... Coming Out show.
Caitlyn was seen being greeted by her partner Sophia Hutchins, before having a sweet moment with her daughter.
The former decathlete, 70, called Kendall “My baby!” before adding the show was "hard" and reminding her daughter she had not used a mobile phone for a month.
Kendall responded: “That's probably good for your soul, honestly.”
Explaining how she found her time Down Under, Caitlyn became emotional as she said: “You know what, I was very, very lucky. The first night, I didn't think I was going to make it, but then the people in the camp were so great, we had so much fun. It made it a lot easier.”
Kendall replied: “Perfect, well then I'm excited to see you."
During the series, viewers had questioned why Kendall and her famous siblings had not publicly shown support for Caitlyn during her time in the jungle.
Kendall then threw her weight behind Caitlyn, writing on Instagram: “Always rooting for you. Strongest person on the [planet]. Just because I’m not posting doesn’t mean I’m not supporting. I love my dad! Everyone chill.”
Kendall and Kim Kardashian also hit back when the families were criticised for not sending Caitlyn a letter to be read out during the show.
Kim wrote on Twitter: "Exactly what Brandon said!!!! NO ONE from I’m A Celeb even reached out and asked for letters, appearances or anything from any Kardashians or Jenners."
Exactly what Brandon said!!!! NO ONE from I’m A Celeb even reached out and asked for letters, appearances or anything from any Kardashians or Jenners. https://t.co/dlzoodwDiz— Kim Kardashian West (@KimKardashian)December 10, 2019
Kendall kept her promise to throw Caitlyn a party and together with her sister Kylie, she arranged for balloons to fill her parent's house when she returned home.
The former Olympic champion Caitlyn is the parent of six children; Casey Marino, Kendall, Kylie, Brandon, Brody and Burt Jenner, and stepparent to Kourtney, Kim, Khloé and Rob Kardashian.