The 2009 Boston mayoral election occurred on Tuesday, November 3, 2009, between incumbent Mayor of Boston Thomas Menino, and Michael F. Flaherty, member of the Boston City Council and former Council president. Menino was re-elected to a fifth term, the first mayor to do so in Boston history. A nonpartisan municipal preliminary election was held on September 22, 2009, where Flaherty and Menino advanced to the general election.
31% of registered voters turned out to vote in the election.
Campaign.
After the preliminary election, Flaherty and fellow-Councillor Sam Yoon, who had finished third, declared they had formed a ticket. If Flaherty were victorious, he vowed to appoint Yoon deputy mayor, a position that had not existed in Boston since the administration of Kevin White, who left office in 1984. Details of the position, including salary, were never finalized.
Primary election.
Endorsements.
 ;templatestyles src="Endorsements box/styles.css"/ ;Michael F. Flaherty
Labor unions
Newspapers and publications
 ;templatestyles src="Endorsements box/styles.css"/ ;Thomas Menino
Labor unions
Organizations
Newspapers and publications
 ;templatestyles src="Endorsements box/styles.css"/ ;Sam Yoon
State officials
Individuals
Results.
! colspan="5" | Primary election
! colspan=2 style="width: 15em" |Party
! style="width: 17em" |Candidate
! style="width: 5em" |Votes
! style="width: 3.5em" |%
! colspan="3" style="text-align:right;" | Total votes
General election.
Campaign.
Following the preliminary election, Flaherty immediately began an aggressive campaign, attacking Menino as ineffectual. Sam Yoon and Michael Flaherty announced that they would run as a ticket in the general election, with Flaherty pledging to appoint Yoon deputy mayor if he won. Kevin McRea also announced that he would endorse Flaherty.
Endorsements.
Names in bold endorsed after the preliminary election.
 ;templatestyles src="Endorsements box/styles.css"/ ;Michael F. Flaherty
State officials
Local officials
Labor unions
Newspapers and publications
 ;templatestyles src="Endorsements box/styles.css"/ ;Thomas Menino
Labor unions
Organizations
Newspapers and publications
Results.
! scope="col" colspan="2" style="width: 15em" |Party
! scope="col" style="width: 17em" |Candidate
! scope="col" style="width: 5em" |Votes
! scope="col" style="width: 3.5em" |%
! colspan="3" style="text-align:right;" | Total votes
References.
 ;templatestyles src="Reflist/styles.css" / ;
Further reading.
Candidates' websites