Marco Cornaro, also known as Cardinal Cornaro and Cardinal Cornelius, was an Italian Roman Catholic cardinal and bishop.

The House of Cornaro or Corner were a Venetian patrician family in the Republic of Venice and included many Doges and other high officials. The name Corner, originally from the Venetian dialect, was adopted in the eighteenth century. The older standard Italian Cornaro is no longer common in Italian sources referring to earlier members of the family, but remains so in English.