In 1991, Mayor McCallion became the first Mayor of a major municipality to submit the annual operating budget to residents for their input and scrutiny. She is also among the first mayors of major municipalities to be openly committed to a pay-as-you-go philosophy. The City has not had to borrow money since 1978 and is currently debt-free. Mayor McCallion also established the Greater Toronto Area (GTA) Mayors' Committee in 1992. She brought together the 30 GTA Mayors, later adding the Chair of Metro Toronto and the four Regional Chairs to work co-operatively for the economic promotion of the GTA. From 1992 to January 2000, the Committee, chaired by Mayor McCallion, was a strong voice on key issues affecting the future of the GTA. As part of that effort, she is a founder and Honorary Co-chair of the Greater Toronto Marketing Alliance. In 1996, Mayor McCallion was appointed to the "Who Does What" Panel established by the Province to review the delivery and funding of government services. She was also appointed to two sub-panels: Assessment and Property Taxation Reform, and Emergency Services.

In addition, the Mayor represented the Association of Municipalities of Ontario (AMO) on the Electricity Transition Committee for the Ministry of Electricity, Science and Technology.  In February 2002, Mayor McCallion was appointed Chair of the Central Ontario Smart Growth Panel by the Hon. Chris Hodgson, Minister of Municipal Affairs. The panel, made up of 22 local government officials and business leaders, advised the provincial government on how to plan for growth for the central region in both the short and long term. In addition to the pressing issue of growth, the panel looked at other issues including gridlock and waste disposal. The panel, the largest in the province, includes the cities of Brantford and Kawartha Lakes, the Counties of Dufferin, Simcoe and Peterborough, the Regions of Niagara, Waterloo, Halton, Peel, York and Durham, as well as the City of Toronto.

Mayor McCallion has played a leading role for women in politics. She is the first woman to hold such significant positions as President of the Streetsville and District Chamber of Commerce; President of the Anglican Young Peoples' Association of Canada; Mayor of Streetsville and Mayor of Mississauga. She was chosen one of the "American Women of the Year" in Who's Who of American Women (which refers to North American women). Mayor McCallion also holds Germany's highest individual honour, the Cross of the Order of Merit of the Federal Republic of Germany, for her role in bringing German companies to Canada. In addition, Her Worship has been awarded the Paul Harris Fellowship by Rotary International in 1985 and 1992, awarded the Lions International President's Award, awarded the Helen Keller Fellowship from the Mississauga Lions Clubs and named a Melvin Jones Fellow for dedicated humanitarian services by Lions Clubs International.