The Nikki Catsouras photographs controversy concerns the leaked photographs of Nicole "Nikki" Catsouras (March 4, 1988 – October 31, 2006), who died at the age of 18 in a high-speed car crash in Lake Forest, California, after losing control of her father's Porsche 911 Carrera and colliding with a tollbooth. Photographs of Catsouras's badly disfigured body were published on the internet, leading her family to take legal action for the distress this caused.

According to Newsweek, the Catsouras "accident was so gruesome the coroner wouldn't allow her parents to identify their daughter's body". Photographs of the scene were taken by California Highway Patrol (CHP) officers as part of standard fatal traffic collision procedures. These photographs were forwarded to colleagues and leaked onto the Internet.

Two CHP employees, Aaron Reich and Thomas O'Donnell, admitted to releasing the photographs in violation of CHP policy. O'Donnell stated in interviews that he only sent the photos to his own e-mail account for viewing at a later time, while Reich stated that he had forwarded the pictures to four other people. Catsouras's parents discovered the photographs posted online. The pictures had gained much attention, including a fake MySpace tribute page that contained links to the photographs. People anonymously e-mailed copies of the photos to the Catsouras family with misleading subject headers, in one case captioning the photo sent to the father with the words "Woohoo Daddy! Hey daddy, I'm still alive." This led the Catsouras family to withdraw from Internet use and, concerned that their youngest daughter might be taunted with the photographs, to begin homeschooling her.