The town of Cottanello owes its name to the family of Aurelii Cottae, a branch of the family Aurelia, which owned a large country manor here.
In the eleventh century the village is mentioned in the ‘Chronicon Farfense’ as an asset subject of a Lombard gentleman who then donated it to the Abbey of Farfa. In the twelfth century it became part of the property of the Church and from the middle of the fifteenth century was given to the Orsini to control. For two years it was at war with Rieti for the domain of Montecalvo, a strategically important fortress.
In 1572 it withstood the attack of the Spanish militias and Landsknechts (German mercenary veterans from the sack of Rome). In 1799 it was burned down by the French for having opposed their plans.