Nikola Zadranin (Latin: Nicolaus de Iadera) was a prelate of the Catholic Church who served as the bishop of Duvno from 1460. The date of the end of his episcopate remains unknown.
Nikola, a Franciscan born in Zadar, was appointed the bishop of Duvno on 2 January 1460, as it is evident from the consistorial minutes from that period. The circumstances of his appointment were complicated, as the territory of the diocese was a domain of Stjepan Vukčić Kosača, a nobleman who was a member of and the protector of the Bosnian Church, in conflict with the Catholic King Thomas. Stjepan's domains were at the time ravaged by the Ottomans, the allies of his son Vladislav Hercegović, with whom he was also in conflict. During 1461, Nikola sent the Pope several requests, granted to him with the intercession from the archbishop of Zadar Maffeo Valaresso. Due to the Ottoman incursions, Nikola, like the local knyaz Pavao Klešić and many influential people from the area, fled. For some time, Nikola resided in his native Zadar. At the end of July and early August 1463, Nikola was in Venice with the papal delegate Cardinal Bessarion, with a task to convince the Republic of Venice to go to the war against the Ottomans. Bessarion appointed Nikola to preach for the Crusade in the areas of Furlania and Istria. Nikola went preaching in August 1463 and, at the same time, tried to get his transfer in Gemona, in the region of Furlania. On 3 April 1464, the Gemona city council accepted him as their bishop; however, it remains unknown whether the appointment was confirmed by the Pope or whether he was relegated to his episcopal duties in Duvno. Dominik Mandić wrote that the Holy See probably didn't allow the transfer and forced him to either to return to Duvno or the nearby Dalmatian town from where he could administer the diocese. Nothing is known about Nikola after 1464, and by the time of the appointment of his successor Vid of Hvar in 1489, he was dead for a long time.