Christa was born in New York City, daughter of model Bonnie Trompeter. As a toddler, Christa Miller was photographed by the acclaimed Francesco Scavullo for an Ivory Snow ad with her mother, throwing her into entertainment at a very young age. At age 3, she appeared on the cover of "Redbook". Christa aspired to be an actress, but her father wanted her to be a lawyer, and her mother, a 1960s supermodel, wanted her to avoid the entertainment business due to its difficulty and stress. Despite her parents' request, she pursued a modeling career. At age 16, she landed her first commercial, for Polaroid cameras, and has been acting ever since. Miller is married to Scrubs and Cougar Town creator Bill Lawrence. They have 3 children.
Miller was previously best known for her role as Kate O'Brien in The Drew Carey Show, and Jordan Sullivan in Scrubs. She has also appeared in the shows Northern Exposure, Seinfeld, Party of Five, The Fresh Prince of Bel-Air. She can be seen in the films Deceived and Love and Happiness.