Duje Bonacic (born 10 April 1929) is a retired Croatian rower who won a gold medal in the coxless four event at the 1952 Summer Olympics.Bonacic was born in Split to Croatian father and Slovenian mother; he had an elder brother Vojko and a sister Nevenka.
He graduated in natural sciences in Zagreb, and took up rowing to build muscles, as he weighed only 56 kg with a height of 183 cm at the time.
After retiring from competitions he worked as a professor of geography, meteorology and oceanography at maritime schools and also served as a coach and referee in rowing and sailing.After the death of Željko Cajkovski on November 11, 2016, he became the oldest Croatian Olympic medal winner.