The municipal elections in Bologna took place on 3 and 4 October 2021. The incumbent Mayor of Bologna was Virginio Merola of Democratic Party, who won the 2016 Bologna municipal election. The centre-left candidate Matteo Lepore won in a landslide with 62% of votes, becoming the most voted mayor since the introduction of direct elections in 1995.
The voting system is used for all mayoral elections in Italy, in the cities with a population higher than 15,000 inhabitants. Under this system, voters express a direct choice for the mayor or an indirect choice voting for the party of the candidate's coalition. If no candidate receives 50% of votes during the first round, the top two candidates go to a second round after two weeks. The winning candidate obtains a majority bonus equal to 60% of seats. During the first round, if no candidate gets more than 50% of votes but a coalition of lists gets the majority of 50% of votes or if the mayor is elected in the first round but its coalition gets less than 40% of the valid votes, the majority bonus cannot be assigned to the coalition of the winning mayor candidate.
The election of the City Council is based on a direct choice for the candidate with a maximum of two preferential votes, each for a different gender, belonging to the same party list: the candidate with the majority of the preferences is elected. The number of the seats for each party is determined proportionally, using D'Hondt seat allocation. Only coalitions with more than 3% of votes are eligible to get any seats.
This is a list of the parties (and their respective leaders) which will participate in the election.
Notes: if a defeated candidate for Mayor obtained over 3% of votes, he/she is automatically elected communal councilor (Battistini); see Italian electoral law of 1993 for Comuni. The candidate elected Mayor is not a member of communal council, but Merola votes in the communal council (see Italian electoral law 1993).