Teresa Fidalgo is a figure central to a widely circulated urban legend or digital chain mail, often associated with a supposed ghost or supernatural entity. The story involves three friends who encounter a woman named Teresa Fidalgo, who, according to the legend, has been dead for 30 years. She famously replies with "Don't look back" and her face is described as pale and decaying after the encounter. The story has been around since 2003 and is widely believed to be an online legend.