She was first elected to Parliament in 1992. Opačić was born in Zagreb, Croatia, then part of Yugoslavia, where she attended elementary and secondary school. She was re-elected to the Parliament in 2000, 2003 and 2007.
She is one of the closest associates of Prime Minister Zoran Milanović.
She is one of four vice-presidents of the Social Democratic Party of Croatia, the main centre-left political party in the Croatian Parliament. She studied political science at the University of Zagreb, graduating in 1991. In 1992, Opačić became the party"s vice-president and entered the Parliament of Croatia as a representative of the Serbs of Croatia.
In 1990, inspired by Ivica Račan, she became a member of the Social Democratic Party of Croatia.
