Antunović descended from an old noble family and studied in Kalocsa, Subotica, Pécs and Szeged. He graduated from the Roman Catholic seminary in Kalocsa, and in 1842 became the priest of the parish in the village of Bácsalmás. He was versed in several languages and closely followed the world events at the time, especially in Croatia, where he befriended the members of the Illyrian movement, including the likes of Josip Juraj Strossmayer, Ivan Kukuljević, Franjo Rački, Ivan Mažuranić, Ilija Okrugić, Juraj Dobrila.