Guarino Foscari (c. 1080 - 6 February 1158) was an Italian Catholic Augustinian canon regular and also the Cardinal-Bishop of Palestrina from December 1144 after his relative Pope Lucius II elevated him into the cardinalate.

At the age of 59 he was elected to fill an opening that the death of the bishop of Pavia created[3] but evaded his episcopal consecration when he climbed out of a window.

During the Advent season of 1144, Pope Lucius II sent for him and he again attempted to avoid higher office.

He also bestowed on him a number of gifts suitable to a person of his new standing, including some fine horses, which Guarino sold and distributing the funds to the poor.

He was bishop for thirteen years and remained out of the troublesome Roman politics that so defined the time and temperament of Rome.