The Donation of Sutri was an agreement reached at Sutri by Liutprand, King of the Lombards and Pope Gregory II in 728. At Sutri, the two reached an agreement by which the city and some hill towns in Latium (like Vetralla) were given to the Papacy, "as a gift to the blessed Apostles Peter and Paul" according to the Liber Pontificalis. The pact formed the first extension of papal territory beyond the confines of the Duchy of Rome and was the first of two land transfers from Liutprand to the Church of Rome.

The Lombards had long been adherents to the Christian sect of Arianism, but they had converted to Catholicism over time. After his election as King of the Lombards in 712, Liutprand faced a series of challenges from the strength of aristocratic families and the threat of secession from the grand duchies in his domain. The duchies of Spoleto and Benevento in Langobardia Minor were particularly autonomous from Liutprand's central power and were separated from the rest of the kingdom by the informal division of the Byzantine Corridor that ran through the center of Italy, from Rome to north of Ravenna.

Liutprand began to centralize the power of his kingdom. Meanwhile, he found support from Rome and the Papal State once disputes over iconoclasm turned them against the Byzantine Empire, which controlled the territory that divided it into two parts. Liutprand seized the moment when the Italian territories governed by the Byzantines rejected the emperor Leo III the Isaurian's support of iconoclasm. Liutprand's military campaign began with his goal to take the territory that divided Langobardia in two—the duchy of Rome and the Byzantine Corridor.

When the Pope understood Liutprand's intentions—that he would probably decide to conquer Rome—he felt endangered. For many years, the Byzantine Empire had ceased to intervene militarily for Rome, using its energies only for the defense of Ravenna. The course of Liutprand's campaign changed, however, when in 728, the Lombards conquered the fortress of Narni, the strategic center of the Via Flaminia. Having lost the Roman road, the Byzantines concentrated their defenses upon the Via Amerina [it], the only Roman road that left Rome and crossed Umbria and Picenum.

Controlling the Via Amerina were the fortresses of Todi, Amelia, and Orte. Further south, the castra of Bomarzo, Sutri, and Blera safeguarded the Via Cassia. In 728, Liutprand took the castle of Sutri, which held strategic importance in the duchy of Rome and dominated the highway at Nepi on the roads to Perugia and Tuscany.

Pope Gregory II asked Liutprand directly to renounce the territories he had just conquered and to return them to the control of the Byzantine Exarchate of Ravenna. By that time, Liutprand had already quelled the rebelling duchies of Spoleto and Benevento. Softened by the entreaties of Pope Gregory II, he restored Sutri "as a gift to the blessed Apostles Peter and Paul" directly to the Papal State. According to Gustav Schnürer,

This expression of the "Liber pontificalis" was erroneously interpreted to mean that in this gift the beginning of the States of the Church was to be recognized. This is incorrect inasmuch as the popes continued to acknowledge the imperial Government, and Greek officials appear in Rome for some time longer. True it is, however, that here for the first time we meet the association of ideas on which the States of the Church were to be constructed. The pope asked the Lombards for the return of Sutri for the sake of the Princes of the Apostles and threatened punishment by these sainted protectors. The pious Liutprand was undoubtedly susceptible to such pleas, but never to any consideration for the Greeks. For this reason he gave Sutri to Peter and Paul, that he might not expose himself to their punishment. What the pope then did with it would be immaterial to him.

The pact was the first extension of Papal territory beyond the confines of the Duchy of Rome.