Research done in 2010 by Harvard Professor Henry Louis Gates, Jr. for the PBS series Faces of America showed that Yamaguchi's heritage can be traced back to Wakayama and Saga prefectures in Japan and that her paternal grandfather, Tatsuichi Yamaguchi, immigrated to Hawaii in 1899.
Yamaguchi and her siblings, Brett and Lori, grew up in Fremont, California. Yamaguchi studied from independent studies and then she graduated from Mission San Jose High School. While at Mission, Kristi's excellence in skating prompted a "Kristi Yamaguchi Day" on February 24, 1989. Mission held an assembly honoring her, where she was presented with an honorary varsity jacket.
Yamaguchi began skating and taking ballet lessons, as a child, as physical therapy for her club feet.
With Rudy Galindo she won the junior title at the U.S. championships in 1986. Two years later, Yamaguchi won the singles and, with Galindo, the pairs titles at the 1988 World Junior Championships; Galindo had won the 1987 World Junior Championship in singles. In 1989 Yamaguchi and Galindo won the senior pairs title at the U.S. Championships. They won the title again in 1990.
As a pairs team, Yamaguchi and Galindo were unusual in that they were both accomplished singles skaters, which allowed them to consistently perform difficult elements like side by side Triple Flip jumps, which are still more difficult than side by side jumps performed by current top international pairs teams. They also jumped and spun in opposite directions, Yamaguchi counter-clockwise, and Galindo clockwise, which gave them an unusual look on the ice. In 1990, Yamaguchi decided to focus solely on singles. Galindo went on to have a successful singles career as well, winning the 1996 U.S. championships and the 1996 World bronze medal.
In 1991, Yamaguchi moved to Edmonton, Alberta, to train with coach Christy Ness. There, she took psychology courses at the University of Alberta. The same year Yamaguchi placed second to Tonya Harding at the U.S. championships, her third consecutive silver medal at Nationals. The following month in Munich, Germany, Yamaguchi won the 1991 World Championships. That year the American ladies team, consisting of Yamaguchi, Harding and Nancy Kerrigan, became the only national ladies team to have its members place first, second and third at Worlds. In 1992, Yamaguchi won her first U.S. title and gained a spot to the 1992 Winter Olympics in Albertville, France. Joining her on the U.S. team were again Kerrigan and Harding. While competitors Harding and Japan’s Midori Ito were consistently landing the difficult triple axel jump in competition, Yamaguchi instead focused on her artistry and her triple-triple combinations in hopes of becoming a more well-rounded skater. Both Harding and Ito fell on their triple axels at the Olympics (though Ito successfully landed the jump later on in her long program after missing it the first time), allowing Yamaguchi to win the gold, despite errors in her free program, including putting a hand to the ice on a triple loop and a double salchow instead of a planned triple. Yamaguchi went on to successfully defend her World title that same year.
Kristi Yamaguchi turned professional after the 1991–92 competitive season. She toured for many years with Stars on Ice and also participated in the pro competition circuit.
In 1996, Yamaguchi established the Always Dream Foundation for children. The goal of the foundation is to provide funding for after school programs, computers, back-to-school clothes for underprivileged children, and summer camps for kids with disabilities. Commenting in 2009, she explained her inspiration for the project: "I was inspired by the Make-A-Wish foundation to make a positive difference in children’s lives. We’ve been helping out various children’s organizations, which is rewarding. Our latest project is a playground designed so that kids of all abilities can play side by side. That’s our focus now."
Currently her Always Dream Foundation (http://www.alwaysdream.org/) is focused on early childhood literacy with a statement of "Empowering Children to reach their dreams through education and inspiration." ADF has partnered with "Raising a Reader" to launch a reading program in schools throughout California and eventually nationwide. The foundation is also providing a language arts program "Footsteps to Brilliance" to kindergarten and first grade. Both programs integrate innovative technology into the classrooms.
Yamaguchi is the author of Always Dream, Pure Gold, and Figure Skating for Dummies. In 2011, she published an award-winning children's book, Dream Big, Little Pig, which was #2 on the New York Times bestseller list, and received the Gelett Burgess Children's Book Award; a portion of the proceeds went to the Always Dream Foundation to support early childhood literacy programs. A sequel, It's a Big World Little Pig, is scheduled to be published March 6, 2012.
Yamaguchi made a fitness video with the California Raisins in 1993 called "Hip to be Fit: The California Raisins and Kristi Yamaguchi". She has appeared as herself on Everybody Loves Raymond and in D2: The Mighty Ducks, Frosted Pink, and the Disney Channel original movie Go Figure. Yamaguchi has also performed in numerous television skating specials, including the Disney special Aladdin on Ice, in which she played Princess Jasmine.
In 2006 Yamaguchi was the host of WE tv series Skating's Next Star, created and produced by Major League Figure Skating.
In 2010 Yamaguchi worked as a daily NBC Olympics skating broadcast analyst on NBC's Universal Sports Network. During the 2010 Winter Olympics, Kristi was also a special correspondent for the Today Show.
Early 2012, Yamaguchi created a woman's active wear line focused on function, comfort, and style to empower women to look good and feel good. The lifestyle brand is called Tsu.ya by Kristi Yamaguchi. Tsu.ya donates a portion of its proceeds to support early childhood literacy through Yamaguchi's Always Dream Foundation. On May 20, 2008, Kristi Yamaguchi became the champion of the sixth season of ABC's reality program Dancing with the Stars, in which she was paired with Mark Ballas, defeating finalist couple Jason Taylor and Edyta Śliwińska. Yamaguchi made a special appearance in the finale of the sixteenth season where she danced alongside Dorothy Hamill.
Since July 8, 2000, she has been married to Bret Hedican, a retired professional hockey player she met at the 1992 Winter Olympics when he played for Team USA. Yamaguchi and Hedican reside in Northern California with their two daughters, Keara Kiyomi (born 2003) and Emma Yoshiko (born 2005). In 2011, she authored a children's book with illustrator Tim Bowers.