Donatus of Zadar was an 8th and 9th-century Catholic bishop and diplomat from the Dalmatian city-state of Zadar. Serving during a period of significant political shifts, he acted as an ambassador for Dalmatian cities, meeting with Charlemagne in Thionville around 805. He is historically recognized for his role in negotiating borders between the Frankish Empire and the Byzantine Empire. He is commemorated as a saint in the Catholic tradition, with his feast day observed on February 25.