Nogent-le-Roi () is a commune in the department of Eure-et-Loir in the Centre-Val de Loire region in France. In January 1973 it absorbed the former commune Vacheresses-les-Basses.
It is located 27 kilometres north of Chartres and 18 kilometres south-east of Dreux.
Population data refer to the commune in its geography as of January 2025.
The town is twinned with Heddesheim near Mannheim in Germany.