Kardashian, 36, said she and Richie, 39, were school friends before they started working together.
Richie, who is Lionel Richie’s adoptive daughter, became known for appearing alongside her fellow socialite Paris Hilton in The Simple Life TV show.
Kardashian became famous for starring in Keeping Up With The Kardashians, but revealed she worked for Richie “five faces ago” – a joke about her own cosmetic surgery procedures.
Speaking to Simon Huck on his Emergency Contact podcast, she said: “I was Nicole Richie’s assistant and you were Jonathan Cheban’s assistant and we met five faces ago.
“I went to school with her. She was one of my best friends growing up and we were just really, really close and then when she started doing Simple Life – I think it was after Simple Life – she just needed some help and I just needed a job.”
Kardashian’s sister, Kim, worked as Hilton’s assistant before becoming one of the world’s most famous women.
Keeping Up With The Kardashians will end next year after 20 seasons.
Reflecting on the decision to call it a day, Kardashian said: “It’s sad, but we’ve been doing this for 15 years. We get two weeks off a year. It’s exhausting.
“We’re all in a different place in our lives and some of us need a nap. It’s hard because I’m not good with change, but that doesn’t mean I don’t need a break.”
