Jillian Michaels (born February 18, 1974) is an American personal trainer, businesswoman, author and television personality from Los Angeles, California. Michaels is best known for her appearances on NBC, particularly The Biggest Loser. She has also made an appearance on the talk show The Doctors. In fall 2015, she hosted and co-judged a series on Spike titled Sweat, INC. In January 2016, her reality television series Just Jillian premiered on E!.
Michaels was born in Los Angeles, California, the daughter of JoAnn, a psychotherapist, and Douglas McKarus, a lawyer. She was raised in Santa Monica. Michaels has recalled a traumatic childhood that included night terrors, her parents' divorce, and suffering verbal abuse by classmates as a 5-foot, 2-inch, 175-pound eighth-grader.
Michaels attended California State University, Northridge, supporting herself as a bartender and personal trainer during that time. After working briefly as an agent with International Creative Management, in 2002, Michaels opened the sports medicine facility Sky Sport & Spa in Beverly Hills.