Tess Gerritsen (born Terry Tom; June 12, 1953) is the pseudonym of Terry Gerritsen,an American novelist and retired general physician.

Tess Gerritsen is the child of a Chinese immigrant and a Chinese-American seafood chef. While growing up in San Diego, California, Gerritsen often dreamt of writing her own Nancy Drew novels. Her first name is Terry; she decided to feminize it when she was a writer of romance novels. Although she longed to be a writer, her family had reservations about the sustainability of a writing career, prompting Gerritsen to choose a career in medicine. In 1975, Gerritsen graduated from Stanford University with a BA in anthropology, intrigued by the ranges of human behavior. She went on to study medicine at the University of California, San Francisco.[5] She received her medical degree in 1979 and started work as a physician in Honolulu, Hawaii.