Kathleen Marie Ireland was born on March 20, 1963, in Glendale, California, to John Ireland, a labor union organizer, and Barbara Ireland, a charity worker. She was discovered when she was 17 by an agent at Elite Model Management and began working as a model before graduating San Marcos High School in Santa Barbara, California. 

At 19, Kathy began her legendary relationship with Sports Illustrated. Photos of Kathy were seen throughout the glossy's pages for 13 consecutive years, from 1984 to 1996, landing the cover of three of its issues. Her first was the 25th Anniversary Swimsuit Edition, which is still the magazine's best-selling issue to date. For her third, she joined fellow SI favorites Elle Macpherson and Rachel Hunter, who, like Kathy, was pregnant at the time. 

In between modeling jobs, Kathy took to the screen and appeared in several film and television roles, including guest spots on Melrose Place, Suddenly Susan, and Touched by an Angel. She began a series of fitness videos and, in 1993, lent her name to a line of socks for Kmart, which eventually led to her own clothing collection. Kathy's immensely popular line inspired her to start a brand marketing company, Kathy Ireland World Wide. By 2005, Kathy's products were sold at over 50,000 locations in 15 countries and generated an estimated $1.4 billion in retail sales. Her achievements prompted Forbes to name her the "prototype for model-turned-mogul" in an article by Liz Smith on the trend of the so-called "modelpreneurs."

As if modeling and business weren't enough, Kathy has also found success in publishing. She has written three children's and two self-help books. Her sixth is due in late fall of 2009.

A devout Christian, Kathy has been married to her husband, Dr. Greg Olsen, since 1988. The couple resides in southern California with their three children, Eric, Lily, and Chloe.