[1] According to the Italian Constitution, the mayor of Siena is member of the city council.

The mayor is elected by the population of Siena, who also elects the members of the city council, controlling the mayor's policy guidelines and is able to enforce their resignation by a motion of no confidence.

The mayor is entitled to appoint and release the members of their government.

Since 1993 the mayor is elected directly by Siena's electorate: in all mayoral elections in Italy in cities with a population higher than 15,000 the voters express a direct choice for the mayor or an indirect choice voting for the party of the candidate's coalition.

Since 1993, enacting a new law on local administrations, the Mayor of Siena is chosen by direct election, originally every four, and since 2001 every five years.