There were a number of open seats as two sitting councillors, Rob Ford and Joe Pantalone, ran for mayor, while incumbents Case Ootes, Kyle Rae, Adam Giambrone, Michael Walker, Mike Feldman, Brian Ashton, and Howard Moscoe did not seek re-election.

This was the first election to take place in Toronto since the enactment of a new fund raising by-law whereby unions and corporations could not donate to candidates.

The nomination period for the 2010 municipal election opened on Monday, January 4, 2010 and closed on Friday, September 10, 2010.

At the end of the campaign there were three major candidates who were included by the media in public opinion polls and mayoral debates: winner Rob Ford, Joe Pantalone, and George Smitherman.

There were a number of open seats, as sitting councillors Joe Pantalone and Rob Ford chose to run for mayor, while long-serving incumbents Case Ootes, Kyle Rae, Adam Giambrone, Mike Feldman, Michael Walker, Brian Ashton and Howard Moscoe announced their retirements.

One notable initiative in 2010 was Better Ballots, an advocacy group which sponsored a debate concerning municipal voting reform on June 1.

City Clerk, Uli Watkiss said in a statement, "The decision to proceed with a by-election and resolve this matter as quickly as possible is in the best interest of the public, the individuals directly affected, and the workings of Council.

In a related judgement, they also ruled that Cusimano incorrectly voted in the Ward 9 election because he lived in another riding.

[29] Incumbent Adam Giambrone dropped out of the mayor's race on February 10 and subsequently announced he would not run for re-election in Ward 18.

Veteran councillor Kyle Rae, who held a seat on council since 1991, announced that he would not be running for re-election.