Ernsborough (modern: "Irishborough") is an historic Saxon estate dating from the 9th or 11th century, situated in the parish of Swimbridge in Devon, England, about 2 miles south-east of the village of Swimbridge. It is best remembered today for having contained during the 14th century a high-status mansion house occupied by the Mules or De Moels family, closely related to Baron Moels of Somerset.