The main opponent Dragan Primorac, supported by the conservative HDZ which holds the government power in Croatia, received barely 20 percent of the votes in the first round of voting two weeks ago.
He is therefore not expected to be able to challenge Milanović, who with 49 percent of the votes in the first round, almost secured the victory already then.
Zoran Milanović has previously been the leader of the Social Democrats but has made a political shift and is now sharply critical of both the EU and NATO. He has also criticized the sanctions against Russia directed at the country due to the war in Ukraine.
The President of Croatia has some power in the country's foreign and security policy. He is also the commander-in-chief of Croatia's armed forces.
The polling stations close at 19 Swedish time.
