Gerardo da Sesso (c. 1160 – 16 December 1211) was an Italian monk, bishop and cardinal of the Catholic Church.
Gerardo came from a prominent Emilian family with Ghibelline leanings. He received a theological education, even penning a summa of his own, before joining the Cistercians. He was the abbot of Tiglieto from 1205 until 1209, bishop-elect of Novara from 1209 until his death and cardinal bishop-elect of Albano from April 1211 until his death. He was elected archbishop of Milan in 1211, but the election was irregular and he ignored it.
He was a staunch ally of Pope Innocent III. From when he was first made a visitator et provisor of the region of Lombardy in 1205 or 1206 until his death, he worked ceaselessly for the reform of the Lombard clergy. After 1210, in the contest over the imperial throne, he strove for the Ghibelline candidate, Frederick II, against the Guelph Otto IV. In April 1211, he was promoted to apostolic legate of Lombardy. One of his first legatine acts was to defend the Humiliati. He was never consecrated and was only ever a bishop-elect.