Marcantonio Barbaro (1518–1595) was an Italian diplomat of the Republic of Venice.
On the death of Francesco Barbaro, Marcantonio and his elder brother Daniele Barbaro jointly inherited a country estate at Maser. There was already a house on the estate, but the brothers replaced it with a new house designed for them by the architect Palladio; this Villa Barbaro is now preserved as part of the World Heritage Site “City of Vicenza and the Palladian Villas of the Veneto“. The brothers probably had some input in the design of the building. Daniele was a published author whose interests included architecture. Marcantonio Barbaro was an amateur sculptor, and seems to have focused mainly on the garden of the new house (in particular, a water feature, the nymphaeum).
Towards the end of Palladio’s life, Marcantonio commissioned him to design a circular chapel, the Tempietto, to serve the Maser estate, and he personally supervised its construction. However, Marcantonio was not buried at Maser, but rather in the family chapel in San Francesco della Vigna in Venice.