Donyatt is a village and civil parish in Somerset, England, situated at the source of the River Isle 5 miles (8.0 km) north of Chard in the South Somerset district. The village has a population of 347. The parish includes the hamlet of Peasmarsh.

The River Isle flows from its source near Combe St Nicholas, through Somerset, England and discharges into the River Parrett south of Langport near Midelney.