Kimberly Lyn "Kim" Lyons (born May 5, 1973) is an American athlete, personal trainer, nutritionist, and fitness model who has appeared on the covers of many health and fitness magazines and is known for her role as a trainer on the United States version of the NBC reality television show The Biggest Loser. Lyons originally replaced fellow trainer Jillian Michaels in season 3, but competed against Michaels when she returned in season 4. Lyons did not return for season 5, and has not made an appearance since. She appeared at the 2008 Miss America pageant as a panelist, and wrote a book entitled Kim Lyons: Your Body, Your Life.
Lyons attended Colorado State University and majored in Human Development and Nutrition, Although she had originally intended to become an airline pilot, Lyons changed her major because of her "love and passion for health and fitness". After her graduation in 1995, Lyons began teaching aerobics, which led to her compete in the famous Galaxy Fitness competition. In 2002, Lyons earned her Pro Card as an IFBB fitness athlete. She is also a model who poses in pageants, and has appeared on many magazine covers.
Lyons lives in Hermosa Beach, California with her husband, German bodybuilder Gunter Schlierkamp. She was previously married to Andrew Lyons, an F-16 pilot.