The River Hor is a short river in the county of Norfolk, England. It runs 13.3 kilometres (8.3 mi) east from its source near Felthorpe to its confluence with the River Bure near Wroxham.

The name of the river is probably a back-formation from the name of villages that it flows through. The village of Horsford has a name meaning "ford that horses can cross", so the river's name may be formed from that.