The Fox River is a stream in Davis, and Van Buren counties of Iowa, and Clark County of Missouri. It is a tributary of the Mississippi River.
The stream headwaters are at near Drakesville and Bloomfield, Iowa. It crosses the Iowa-Missouri border near Mt Sterling, and its confluence with the Mississippi is about six miles south of the confluence of the Des Moines River, near Alexandria at .
The Fox River was named after the Meskwaki or Fox people.
At Wayland, Missouri, the river has an average discharge of 283 cubic feet per second.