The 93-year-old mayor was presiding over her last city council meeting Wednesday before handing over the reigns to incoming mayor Bonnie Crombie.
McCallion — nicknamed “Hurricane Hazel” — has been mayor of the city since 1978 and won her 12th term in 2010.
She announced shortly after winning in 2010 that it would be her last term in office.
Under her leadership, Mississauga became the third-largest city in Ontario and the sixth largest in Canada.
Crombie will be officially sworn in on Dec. 2.
McCallion called her time in office “a wonderful journey."
"I can’t think of a mayor that has been as fortunate as I have been to have the wonderful support of the residents of Mississauga over the years," she said.
Crombie, 54, was the city’s MP from 2008 to 2011 and switched over to the role of councillor in a September 2011 byelection after losing her federal seat.
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