Hazel Mary Muriel McCallion CM OOnt (née Journeaux; February 14, 1921 – January 29, 2023) was a Canadian politician who served as the fifth mayor of Mississauga.

[3][4][5] When the 1979 Mississauga train derailment occurred early in her tenure, she helped oversee evacuation of 200,000 residents from the resulting explosion, fire, and spill of hazardous chemicals.

Before marriage, McCallion played professional women's ice hockey while attending school in Montreal, then worked for engineering firm Canadian Kellogg, and was transferred to Toronto in 1942.

Following her tenure as mayor of Mississauga, McCallion remained an active public figure, serving as the first chancellor of Sheridan College,[6] on the Greater Toronto Airport Authority board, and as a special advisor to the Ontario government.

McCallion received multiple honours including the Order of Canada in 2005, the Order of Ontario in 2020, the Queen Elizabeth II Golden Jubilee Medal in 2002, the Queen Elizabeth II Diamond Jubilee Medal in 2012, and honorary doctorate of law degrees from the University of Toronto, and Ryerson University.

[10] After beginning her career in Montreal with the Canadian division of engineering firm Kellogg, she was transferred to Toronto in 1942, where she helped set up the local office.

[20] During McCallion's terms in office, Mississauga grew from a small collection of towns and villages to one of Canada's largest cities, with much of the growth occurring after the 1976 election of René Lévesque's Parti Québécois government sparked an exodus of Anglophones and corporations from Montreal to the Greater Toronto Area (GTA).

[27] She announced during her final term that she would not be running for re-election in the 2014 municipal elections[28] and endorsed councillor and former federal member of Parliament Bonnie Crombie to replace her as Mayor.

[29] Crombie defeated former city councillor, member of Provincial Parliament and federal cabinet minister Steve Mahoney to win the 2014 municipal election.

[31] In a first-person account for Canadian magazine Confidence Bound, McCallion credited her faith with giving her energy, and said she still did her own household chores.

"[32] On her 90th birthday in 2011, McCallion was assessed by Dr. Barbara Clive, a geriatrician, who stated that "at 90 her gait is perfect, her speech is totally sharp and she has the drive to still run this city.

[34][11] In 2009, McCallion was the focus of public opinion when it was alleged that she failed to disclose a conflict of interest when attending meetings that concerned her son's company, World Class Developments Ltd.[35][36] On October 3, 2011, Judge Douglas Cunningham found McCallion "acted in a 'real and apparent conflict of interest' while pushing hard for a real estate deal that could have put millions of dollars in her son's pocket.

On two of the three issues Mayor McCallion was successful, not because of any prudence or diligence, but only because World Class Developments's project had not progressed at a faster pace.

She was responsible for the formation of Hazel's Hope, a campaign to fund health care for children afflicted with AIDS and HIV in southern Africa.

[53] McCallion was once a board member of the Central Ontario Women's Hockey League, and was instrumental in the construction of the Hershey Centre in Mississauga.

[54] In November 2015, McCallion was appointed chief elder officer (CEO) of Revera Inc., to provide advice and counsel to the senior living sector company.

[55] In September 2011, Sheridan College opened the doors to its Hazel McCallion Campus in Mississauga, which was greatly expanded in 2018, more than doubling its enrollment.

Furthering her ties with the college, in 2016, McCallion was named Sheridan's first chancellor, as part of its bid to attain university status.

[56] In 2017 McCallion was appointed to the board of the Greater Toronto Airport Authority, a position for which she accepted a three-year renewal in April 2022.

[24] Journeaux met her future husband, Sam McCallion (1923–1997),[61] at an Anglican Church congregation in Toronto in 1951; they married on September 29 of that year.