Ordelafo Faliero de Doni (or Dodoni) (d. Zara, 1117) was the 34th Doge of Venice.
He was the son of the 32nd doge, Vitale Faliero de' Doni. He was a member of the Minor Council (minor consiglio), an assembly formed from members of the so-called "apostolic families" that, in oligarchical Venice, assumed the governmental functions of judges, military councilmen, ambassadors and heads of state.
His first name, which is otherwise unknown in Venetian history, is thought to have been derived from a backwards spelling of the Venetian name "Faledro".
During his reign as Doge, Faliero went to war against the Hungarians, ruled at the time by Coloman, which lasted from 1105 to 1115. Faliero succeeded in recapturing Zara and Sebenico.
Afterwards, Faliero was engaged in an expedition to Syria, comprising 100 Venetian ships, which succeeded in conquering a part of Acre. Objects from the local Syrian convent of Christ were taken back to Saint Mark's Basilica.
In Venice, Faliero established the nucleus of what would become the Arsenal.
He was married to Matelda, traditionally portrayed as an ideal of spousal fidelity.
He was killed at Zara during a battle against the Hungarians.