Dragutin Dončić Vjekoslav Heinzel Croatian Union On 18 June 1920 local elections were held in Zagreb, in the Kingdom of Serbs, Croats and Slovenes.

The Croatian Union won a majority of seats and Vjekoslav Heinzel was named the new mayor of Zagreb.

Democratic Party boycotted the elections and asked to schedule elections for the entire city assembly.

On 17 August 17, 1920 Vjekoslav Heinzel was elected mayor with 27 votes, while Vladimir Prebeg from the Party of Rights received eight votes.

Eight votes were invalid (blank ballots).