Toronto residents are going to the polls to elect a new mayor, six weeks after Mayor Rob Ford dropped his bid for re-election amid health concerns.
Polls suggest John Tory, a businessman, leads Mr Ford's brother Doug Ford and former MP Olivia Chow in the race.
Doug Ford stepped into the race after his brother was diagnosed with a rare, aggressive cancer in September.
Before his diagnosis, Rob Ford, 45, had refused calls to step down after admitting using drugs while in office.
Rob Ford is instead running for the city council seat in his political base in the suburb of Etobicoke, currently held by Doug Ford. He is expected to win that race.
Polls will be open for voting in the mayor's race and all 44 council seats from 10:00 local time (14:00 GMT) to 20:00.
Mr Tory, the former chief executive of Canadian cable firm Rogers and former Progressive Conservative member of the Ontario parliament, ran unsuccessfully for Toronto mayor in 2003.
Ms Chow, a left-of-centre former New Democratic Party MP and widow of national New Democratic Party leader Jack Layton, has fallen in the polls since Doug Ford entered the race.
Turnout has already been high. A record 161,147 people voted early this month, more than double the number in the last election, in 2010.
Mr Ford was diagnosed in early September with a malignant liposarcoma, a rare cancer of the soft tissue which accounts for only 1% of all cancers, He has begun chemotherapy treatment.
He will step down from the mayor's office after a tumultuous four-year term in which he admitted using and purchasing drugs while in office and was captured on film in states of apparent severe intoxication.
Those and other antics led to calls for him to resign and to the city council stripping him of most of his powers.
Rob Ford's troubled mayoralty
- May 2013: A video surfaces apparently showing him smoking crack cocaine
- August 2013: He seems intoxicated in an official appearance at a street festival, later says he has smoked "a lot of marijuana"
- 5 Nov 2013: "I have smoked crack cocaine," the mayor admits, saying he did so "in a drunken stupor"
- 7 Nov 2013: A second video surfaces showing a foul-mouthed Ford threatening to kill an unspecified person
- 14 Nov 2013: Ford makes lewd comments about oral sex and says he might have driven while drunk
- 17 Dec 2013: Ford apologises again, this time for implying, falsely, that a Canadian journalist was a paedophile
- April 2014: Starts re-election campaign
- May: Halts campaign to begin treatment for substance abuse, as more videos surface
- September: Diagnosed with rare tumour