Nogent-le-Rotrou is a commune in the west of the Eure-et-Loir department in north-central France. It is a sub-prefecture and is located on the Huisne River, 56 kilometers west of Chartres on the RN23. It was the former capital of the county of Perche.
The most famous site in Nogent-le-Rotrou is the Château Saint Jean.