Kimberly Ann Guilfoyle was born in San Francisco, CA on 9 March 1969 to a mother of Puerto Rican descent and an Irish-American father. Her mother died of leukemia when Kimberly was just ten. She and her brother and sister were raised by her father in a single-parent household.
Kimberly grew up in the the Mission District of San Francisco and graduated from Mercy High School. She then earned a degree from the University of California, Davis, and graduated from the University of San Francisco Law School in 1994. To help pay for the aforementioned education, Kimberly had a brief stint as a Victoria's Secret lingerie model.
After law school Kimberly briefly worked as a prosecutor in San Francisco, but lost her job in 1996 when Terence Hallinan was elected District Attorney and fired fourteen prosecutors. Guilfoyle then spent four years in Los Angeles as a Deputy District Attorney, and prosecuted cases involving narcotics, domestic violence, kidnapping, robbery, arson, sexual assault, and homicide, amongst others. While employed at the Los Angeles District Attorney's Office, Kimberly earned a number of awards including Prosecutor of the Month.
In 2000, Ms. Guilfoyle returned to the San Francisco District Attorney’s Office and was named the Assistant D.A. It was in that capacity that Kimberly gained national attention in 2001 when she successfully prosecuted two defendants for second-degree murder after said defendants' pitbull dogs mauled a woman to death in San Francisco. In December 2001 she married Gavin Newsom, a city supervisor from a prominent family who was elected Mayor in 2003.
In January 2004, Kimberly accepted the host position of Both Sides on Court TV, and took on a role as a legal analyst on Anderson Cooper 360. Citing the strain of a long-distance - indeed, a bi-coastal - marriage, Kimberly filed for divorce from husband Gavin Newsom in January 2005. Their divorce was finalized in February 2006.
Kimberly took over as host of The Lineup on Fox News Channel on 11 February 2006. The show was re-launched with new music and graphics specifically as a vehicle for Ms. Guilfoyle.
Kimberly remains quite visible in San Francisco society as a member of many charitable organizations, and maintains close ties with the Getty family.