Saint-Germain-du-Seudre (French pronunciation: [sɛ̃ ʒɛʁmɛ̃ dy sødʁ], literally Saint Germain of the Seudre) is a small historic town on the Gironde estuary.

It is a commune in the Charente-Maritime department in southwestern France.

The nearest market town is Gémozac.

It is noted for its numerous vineyards, sunflower fields and the former wheat mill located in 'Moulin De La Barre'.

Eutrope Dupon (1823-1897), born in Saint-Germain-du-Seudre, was a deputy (congressman) in the French National Assembly from 1893 to 1897.