Saint-Pierre-de-Plesguen (Breton: Sant-Pêr-Plewenn) is a former commune in the Ille-et-Vilaine department in Brittany in northwestern France.

On 1 January 2019, it was merged into the new commune Mesnil-Roc'h.

[2] Hughes Felicité Robert de Lamennais lived in Saint-Pierre-de-Plesguen during the 19th century.

Inhabitants of Saint-Pierre-de-Plesguen are called saint-pierrais in French.

This Ille-et-Vilaine geographical article is a stub.