Sophie Neveu is the granddaughter of Louvre curator Jacques Saunière. She is a French National Police cryptographer, who studied at the Royal Holloway, University of London Information Security Group.
She was raised by her grandfather from an early age, after her parents were killed in a car accident. Her grandfather used to call her "Princesse Sophie" and trained her to solve complicated word puzzles. As a young girl, she accidentally discovered a strange key in her grandfather's room inscribed with the initials "P.S.". Later, as a graduate student, she had arrived early for a spring-break visit to her grandfather's house in Normandy and, silently horrified, she had observed him participating in the Hieros Gamos, a sex ritual—with his own wife, who was believed to be dead. The incident led to her estrangement with her grandfather for ten years until the night of his murder.
Sophie finds out at the end of the book that she is a descendant of the Merovingians, and a living descendant of the historical Jesus. She first starts suspecting this when Sir Leigh Teabing reveals the truth of the Holy Grail, but dismisses the idea when Langdon tells her that neither her surname nor her grandfather's is a Merovingian name. (The surname Neveu is the French word for "nephew.") In fact, as she later finds out, her parents and ancestors had, for protection, changed their family names of Plantard and Saint-Clair. At the end of the book, she agrees to spend a week in Florence with Robert Langdon.
In the movie, Sophie is portrayed by French actress Audrey Tautou.