Pierre-De Saurel () is a regional county municipality in the Montérégie region in southwestern Quebec, Canada. Originally named Le Bas-Richelieu Regional County Municipality, the name change to Pierre-De Saurel took effect on January 1, 2009. Its seat is in Sorel-Tracy. It is located on the Richelieu River, downstream from La Vallée-du-Richelieu Regional County Municipality at the confluence of the Richelieu and Saint Lawrence River.
The RCM is named after Pierre de Saurel, a captain of the Carignan-Salières Regiment who rebuilt Fort Richelieu in 1666 and later became the area's seigneur.
There are 12 subdivisions within the RCM:
Highways and numbered routes that run through the municipality, including external routes that start or finish at the county border:
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