For a time, Gayheart was engaged to director Brett Ratner and has dated Michael Weatherly. She and actor Eric Dane were married on October 29, 2004. Dane told Flaunt Magazine about how they met:

“It’s probably one of the least interesting stories in the world,” Dane said. “It went basically like this: “‘You wanna go out?’ “‘Yeah, sure.’ Ten months later, we were married.”

On June 13, 2001, Gayheart struck and fatally injured nine-year-old Jorge Cruz Jr. as he illegally crossed a Los Angeles-area street. According to the police report, the child was walking home from school and ran across the street only 160 feet from a crosswalk. While several cars stopped to let him go, Gayheart swerved around them and into a two-way left-turn lane, striking the boy. Her attorney, Steven Lerman, subsequently admitted Gayheart had been using a cell phone during impact.

Cruz died the next day at Los Angeles Children's Hospital. His parents, Jorge Cruz and Silvi