Social Democrat Ivo Josipovic, who pledged to lead Croatia into the European Union and crack down on corruption, has been elected president.
Mr Josipovic, a law expert and classical music composer who is relatively inexperienced in high politics, won 60.3% of the vote in the second round run-off.
He will be Croatia's third president since independence from Yugoslavia in 1991.
Populist Zagreb mayor Milan Bandic, backed by the Roman Catholic church and more conservative voters, took 39.7% of the vote as an independent candidate.
He was expelled from the Social Democrats for insisting on running for president against the party's will.
Mr Josipovic promised to back Prime Minister Jadranka Kosor's drive to implement reforms and fight widespread corruption, as required by Brussels to complete EU accession talks this year.
'I want an uncompromising fight against corruption and organised crime. That is what I promised, that is what we'll achieve,' Mr Josipovic said.
The candidate of the ruling conservative HDZ party failed to make it to the runoff.
