By car: Richelieu is about 30 minutes south of Chinon on the D757, and roughly 1h30 south of Tours. The drive through the Touraine countryside — rolling farmland, vineyards, and occasional château glimpses — is pleasant.
By train: There is no mainline train stop in Richelieu itself. However, the Chemin de Fer de la Touraine, a narrow-gauge tourist railway, runs between Richelieu and Chinon on summer weekends — a charming and historically appropriate way to arrive, since the railway was originally built in the 19th century to connect the town to the wider network. Check schedules as it operates seasonally.
For most visitors, a car is the practical option, particularly if combining Richelieu with other Loire Valley stops.