Here's a look at the candidates:
- Zoran Milanovic -
Smart and driven but also often seen as quick-tempered and arrogant, Milanovic is hoping to stay in office after serving his five-year term.
Since entering office, the 58-year-old incumbent has adopted more populist and often offensive rhetoric targeting political opponents and European Union officials.
The Zagreb-born law graduate, who was among the best students of his generation, has been one of Croatia's main political figures for nearly two decades.
A career diplomat during the country's 1990s independence war, Milanovic later served with Croatia's EU and NATO mission in Brussels.
He entered politics in 1999 by joining the left-wing Social Democrats (SDP), formerly the communist party, and took over its helm in 2007.
He served as prime minister from 2011 to 2016, but after a SDP defeat at the ballot box, Milanovic quit as the party leader and withdrew from politics to work as a consultant.
He made a political comeback in 2019 as an SDP candidate for the presidency.
Earlier this year, Milanovic unexpectedly campaigned in a failed bid to become prime minister during April's parliamentary elections.
During his campaign he repeatedly slammed HDZ over alleged corruption and labelled their leader and his arch-rival Prime Minister Andrej Plenkovic as a "serious threat to Croatia's democracy".
- Dragan Primorac -
The physician and scientist entered politics in the early 2000s, when he was named science and education minister in the HDZ-led government and joined the party in 2007.
A trained paediatrician and expert in genetics and forensics, Primorac made his name as one of the pioneers of DNA analysis in Croatia and helped identify wartime victims whose remains were found in mass graves in the 1990s.
Primorac unsuccessfully ran for the presidency in 2009, which prompted his eviction from the HDZ.
After spending years out of politics, Primorac launched his presidential campaign this year with the hopes of staging a comeback.
Although he is not a member of HDZ, the party has thrown its support behind the candidate.
Primorac's campaign has largely centred on attacking Milanovic, while trying to play up his commitment to family values and patriotism.
Critics have panned the 59-year-old for lacking political charisma, saying he has served as the HDZ's attack dog to target Milanovic.
- Marija Selak Raspudic -
The philosophy professor and centre-right lawmaker is known for her bold and eloquent speeches.
The 42-year-old was born in Zagreb where she graduated with degrees in philosophy and Croatian in 2007.
After briefly working in public relations and as a TV journalist, she joined Zagreb University's philosophy department.
Selak Raspudic entered the parliament in 2020 as an MP of the ultra-conservative Most -- "Bridge" -- party. She was re-elected this year but ditched the party and is running as an independent.
She has advocated for stronger presidential powers, including the introduction of a veto.
"We need a proactive president who will make the most of her powers," she said.
- Ivana Kekin -
The psychiatrist and former activist has served as an MP since 2021 as a member of the green-left Mozemo -- "We Can" -- party.
The left-leaning candidate has vowed to "bring a better life to people", including pledges to improve the ailing public healthcare sector.
A long-time opponent of the ruling conservatives, Kekin made her name as a prominent activist and participated in demonstrations advocating for the rights for women and the LGBTQ community and campaigned for the protection for public areas.
In June, Kekin was elected a member of the European Parliament but later stepped back from taking the position, allowing a fellow party member to take the job.
The 40-year-old psychiatrist is also married to Mile Kekin, the frontman of the Croatian punk-rock band Hladno Pivo.
ljv/ds/ach
© Agence France-Presse