Berengar of Friuli (? - 16 April 924) was a Margrave of Friuli, King of Italy (from 888 on) and Emperor from 915 on.

Berengar I originated from the Carolingians on his mother's side. He was the son of Gisela, a daughter of Louis the Pious, and Eberhard, the Margave of Friuli.

His older brother Unroch III died before his time and Berengar succeeded him as margrave of Friuli around 874. With this his obtained a key position, as the margrave bordered the Slavs and Magyars who where threatening the Italian peninsula. In 888, Berengar succeeded in convincing the Italian nobility to proclaim him King of Italy, even though there certainly were other options for the title. His rival, Guido of Spoleto, tried to outmaneuver him by having Pope Stephen VI crown him Emperor, as well as crowning both him and his son Lambert as King. The coronation was quite controversial because Guido was known as an archrival of the Pope. Nevertheless, Guido succeeded in restoring order in Italy from his bases in Pavia and Rome. Fortunately for Berengar, Pope Formosus invited King Arnulf of the East Franks to Italy in 893 to overthrow Guido. Arnulf sent his illegitimate son Zwentibold, who met up with Berengar. Together, they cornered Guido at Pavia, but did not press their advantage (it is believe that Guido bribed them off). The following year, Arnulf and Berengar defeated Guido at Bergamo and took control of Pavia and Milan. Guido died in 894. His son, Emperor Lambert, defeated an attempt by Berengar to advance on Pavia, but died in a hunting accident days later. Meanwhile, Arnulf, who had been crowned in 896 in opposition to Lambert, had left Italy that same year. It seemed that Berengar would quickly regain his authority.

Outside events would change this, however. Chaos had struck as the first Magyar invasions had commenced. Berengar's defeat at their hands at Brenta River in 899 caused the nobility to question his ability to protect Italy. As a result, they supported another candidate for the throne, Louis of Provence. In 900 Louis marched into Italy and defeated Berengar; the following year he was crowned King and Emperor by Pope Benedict IV. In 902, however, Berengar stuck back and defeated Louis, making him promise not to return to Italy. When he broke this oath by invading the peninsula again in 905, Berengar again defeated him at Verona, captured him, and ordered him to be blinded. Louis returned to Lower Burgundy and ruled for another twenty years as Louis the Blind. Berengar therefore cemented his position as king.

In January 915, Pope John X, after forging an alliance between Beranger and the local Italian rulers, crowned Berengar as Emperor, hoping he could face the Saracen threat in the south of Italy. However, Berengar returned swiftly to the north where Friuli was still threatened by the Magyars. Dissatisfied with the emperor, several Italian nobles invited Rudolf II of Upper Burgundy to take the Italian throne in 922. Moreover, his own son-in-law, the Margrave of Ivrea, rose up against him, incited by Rudolf. Berengar retreated to Verona and had to watch sidelined as the Magyars pillaged the country. Pavia was sacked in 924. That year he was murdered by one of his own men, possibly at the instigation of Rudolf.

There exists an anonymous writing, 'Gesta Berengarii Imperatoris', about the many happenings of his troublesome time.