Kim Kardashian was born in Los Angeles, California, the daughter of attorney Robert Kardashian and Kris Jenner. Robert Kardashian, best known for being O. J. Simpson’s lawyer during his murder trial, died on September 30, 2003. Her mother, Kris, divorced Robert in 1989, and married former Olympian Bruce Jenner in 1991. While attending high school Kardashian worked at her father's music marketing firm, Movie Tunes.

Kardashian has two sisters, Kourtney and Khloe, and one brother, Robert. She also has stepbrothers Burton Jenner; Brandon Jenner; and reality TV star Brody Jenner; stepsister Casey Jenner; and half-sisters Kendall and Kylie Jenner.

In 2000, Kardashian married music producer Damon Thomas; their relationship ended in divorce in 2004. Currently she is dating NFL player Reggie Bush.

Kim Kardashian was little known outside gossip circles until the pornographic home video she had made with then-boyfriend, R&B singer Ray J, was leaked. Vivid Entertainment was the distribution company against which Kardashian had pursued legal action for the ownership of the tape. Kardashian later dropped the suit and settled with Vivid Entertainment for US$ 5 million.

On May 2, 2008, Kardashian released a workout DVD, Workout with Kim Kardashian, and a set of workout cards with the help of trainer Kathy Kaehler.

Continuing the branding of her self-image, in July 2008 Kardashian announced on her personal blog that she is working on her own perfume line to be released in 2009.