Congrier () is a commune in the Mayenne department in north-western France. The town of Congrier belongs to the canton of Cossé-le-Vivien and the arrondissement of Château-Gontier.
The inhabitants of Congrier are called Congriéens; their number in 2016 was 921.
The Semnon has its source in the commune.
The town's surface is 24.3 km<sup>2</sup>. It is situated at an altitude of about 80 meters.