Loredana Marcello (died 12 December 1572) was a Dogaressa of Venice by marriage to the Doge Alvise I Mocenigo (r. 1570-1577).
She was an author of letters and poetry and studied botany, and was regarded as a model of an educated and cultivated renaissance woman in contemporary Venice.
Together with her sisters Bianca, Daria and Maria, she was referred to as fiore de'l secolo (from Italian, flower of the century) and regarded to represent the ideal of the educated renaissance woman for the nobility in Venice, and was, as multi talented, referred to as Giantessa di merito.
She also studied botany, and was a student of a professor of the Biological Garden in Padua, Melchiorre Giuliandino.
Her work is lost, but her botanical research it is noted to have been consulted and put to good use during the epidemic which appeared in Venice few years after her death (1575).