The Triarchy of Negroponte is a crusader state established on the island of Euboea (Italian: Negroponte) after the partition of the Byzantine Empire following the Fourth Crusade.

Partitioned into three baronies (terzieri, "thirds") run by a few interrelated Lombard families, the island soon falls under the influence of the Republic of Venice.

From ca.

1390, the island becomes a regular Venetian colony as the Kingdom of Negroponte (Regno di Negroponte).