Portfolio ministries were titled "department" prior to 1972. Certain ministers held titles such as secretary and commissioners of their portfolio in the past. As much as possible, the following list groups former portfolios as predecessor to current portfolios with similar but not perfectly identical functions/mandate.
Children, Community and Social Services (since 2018) • Department of Public Welfare (1930–67) • Ministry of Social and Family Services (1967–72) • Ministry of Community and Social Services (1972-2002) • Ministry of Community, Family and Children's Services (2002–2003) • Ministry of Children's Services (2003–2004) • Ministry of Children and Youth Services (2004–18) • Ministry of Community and Social Services (2003–18)
Citizenship and Multiculturalism (since 2021) • Ministry of Citizenship (1961–83, 1987–95; 2001–03) • Ministry of Citizenship and Culture (1983–87) • Ministry of Citizenship, Culture and Recreation (1995–2001) • Ministry of Citizenship and Immigration (2003–14, 2016–18) •
Ministry of Citizenship, Immigration and International Trade (2014–16)
Economic Development, Job Creation and Trade (since 2018) (Primary functions relating to industrial policy) • Department of Planning and Development (1944–61) • Department of Commerce and Development (1961) • Department of Economics and Development (1961–68) • Department of Trade and Development (1968–72) • Ministry of Industry and Tourism (1972–82) • Ministry of Industry and Trade Development (1982–85) • Ministry of Industry, Trade and Technology (1985–1993) • Ministry of Economic Development and Trade (1993–95, 1999-2002, 2003–11) • Ministry of Economic Development, Trade and Tourism (1995–99; 2008–11) •
Ministry of Enterprise, Opportunity and Innovation (2002–2003) • Ministry of Economic Development and Innovation (2011–13) • Ministry of Economic Development, Trade and Employment (2013–14) • Ministry of Economic Development, Employment and Infrastructure (2014–16) • Ministry of Economic Development and Growth (2016–18) (for trade promotion) • Ministry of International Trade and Investment (2008–09) •
Ministry of International Trade (2016–18) (for innovation and research policy) •
Ministry of Research and Innovation (2011–16) • Ministry of Research, Innovation and Science (2016–18)
Education (since 1999) or
Colleges, Universities, Research Excellence and Security (since 2025) • Department of Public Instruction (1850–76) • Department of Education (1876-1993) • Department of University Affairs (1964–71) • Ministry of Colleges and Universities (1971–93, 2018–25) •
Ministry of Education and Training (1993–99) • Ministry of Training, Colleges and Universities (1999-2016, 2018–19) • Ministry of Advanced Education and Skills Development (2016–18)
Energy & Mines •
Ministry of Energy and Infrastructure (2007–2010) •
Ministry of Energy, Science and Technology (1997–2002)
Environment, Conservation, and Parks • Ministry of Environment and Energy (1993–1997; 2002)
Finance • Ministry of Treasury and Economics (1978–1993) • Ministry of Financial Institutions (1986–1993) •
Ministry of Revenue (1968–2012)
Indigenous Affairs and First Nations Economic Reconciliation (since 2024) • Native Affairs Directorate (1987–91), Secretariat (1991-2006) • Aboriginal Affairs Secretariat (2006–07) • Ministry of Aboriginal Affairs (2007–16) • Ministry of Indigenous Relations and Reconciliation (2016-2018) • Ministry of Indigenous Affairs (2018–24)
Infrastructure (since 2010) or
Transportation (since 1987) • Board of Works (before
confederation in
Upper Canada) • Department of Public Works (1867-1972) • held by the
Commissioner of Agriculture and Public Works until 1874 • Commissioner of Highways (1900–16, within Department of Public Works) • Department of Public Highways (1916–31) • Department of Highways (1931–71) • Department of Transport (1957–71) • Ministry of Transportation and Communications (1971–1987) •
Ministry of Public Infrastructure Renewal (2003−2008) • (held jointly with Energy 2008-10, with Economic Development 2014-16)
Municipal Affairs and Housing • Ministry of Housing (1973–1981; 1985–1995) • Ministry of Municipal Affairs (1985–1995; 2003–2004)
Labour, Immigration, Training, and Skills Development • Bureau of Labour (1900–19, within Department of Public Works) • Ministry of Labour (1919-2019) • Ministry of Skills Development (1985–1993) • Ministry of Labour, Training and Skills Development (2019–22)
Public and Business Service Delivery and Procurement (since 2022, Procurement added 2024) • Ministry of Financial and Commercial Affairs (1966–72) •
Management Board Secretariat (1971-2005) • Ministry of Government Services (1972–93, 2005–07, 2008–14) • Ministry of Consumer and Commercial Relations (1972–2001) • Ministry of Consumer and Business Services (2003–2005) • Ministry of Government and Consumer Services (2007–08, 2014–22) • Ministry of Small Business and Consumer Services (2008–09) • Ministry of Consumer Services (2009–14)
Solicitor General (existed as such 1972-2002 except for 4 periods held jointly with Correctional Services, resumed this name in 2019) •
Department of the Provincial Secretary (1867-1946) • Department of Reform Institutions (1946–68) • Ministry of Correctional Services (1968–2002, except for 4 periods held jointly with Solicitor General) • Ministry of the Solicitor General and Correctional Services (1985–86, 1987, 1990–92, 1993-99) • Ministry of Public Safety and Security (2002–2003) •
Ministry of Community Safety and Correctional Services (2003–2019)
Tourism, Culture and Gaming and Sport •
Ministry of Culture and Communications (1987–1993) •
Ministry of Culture, Tourism and Recreation (1993–1995) •
Ministry of Tourism (1999–2001) •
Ministry of Tourism, Culture and Recreation (2001–2002) ==Ontario Shadow Cabinet==