| Corbrook Awakening Abilities | Other Public Sector Employers | 2025 | 2 | $164,637 |
| Corbrook Sheltered Workshop | Other Public Sector Employers | 2018 | 1 | $186,371 |
| Corhealth Ontario | Other Public Sector Employers | 2021 | 19 | $155,670 |
| Cornerstone Family Violence Prevention Centre | Other Public Sector Employers | 2025 | 1 | $127,380 |
| Cornwall Community Hospital | Hospitals & Boards of Public Health | 2025 | 304 | $125,159 |
| Cornwall General | Hospitals & Boards of Public Health | 2000 | 1 | $134,066 |
| Cornwall General Hospital | Hospitals & Boards of Public Health | 2003 | 1 | $149,070 |
| Corp. of Haldimand County | Municipalities & Services | 2006 | 5 | $118,147 |
| Corp. of the City of Barrie | Municipalities & Services | 1999 | 1 | $110,730 |
| Corp. of the City of Burlington | Municipalities & Services | 1999 | 4 | $111,183 |
| Corp. of the City of Cambridge | Municipalities & Services | 1999 | 1 | $116,327 |
| Corp. of the City of Cornwall | Municipalities & Services | 1999 | 1 | $105,731 |
| Corp. of the County of Lambton | Municipalities & Services | 2002 | 1 | $113,964 |
| Corp. of the County of Lambton, the | Municipalities & Services | 2001 | 1 | $106,404 |
| Corporation of Haldimand County | Municipalities & Services | 2003 | 2 | $120,182 |
| Corporation of Massey Hall and Roy Thompson Hall | Other Public Sector Employers | 2022 | 18 | $154,205 |
| Corporation of Massey Hall and Roy Thomson Hall | Other Public Sector Employers | 2015 | 12 | $157,095 |
| Corporation of the City of Barrie | Seconded to Ministries | 2017 | 2 | $120,158 |
| Corporation of the City of North Bay | Municipalities & Services | 2025 | 119 | $138,228 |
| Corporation of the City of Thunder Bay | Municipalities & Services | 1996 | 2 | $110,217 |
| Corporation of the City of Waterloo | Municipalities & Services | 1996 | 1 | $103,623 |
| Corporation of the Leeds, Grenville and Lanark District Health Unit | Hospitals & Boards of Public Health | 2024 | 11 | $138,272 |
| Corporation of the Town of Bracebridge | Municipalities & Services | 2006 | 1 | $111,095 |
| Corporation of the Town of Centre Wellington | Municipalities & Services | 2006 | 2 | $111,462 |
| Corporation of the Township of Seguin | Municipalities & Services | 2006 | 1 | $142,446 |
| Corporation of the Township of West Lincoln | Municipalities & Services | 2006 | 1 | $110,240 |
| Corporation of the Township of Wilmot | Municipalities & Services | 2006 | 1 | $103,305 |
| Corporation, Town of Cobourg | Municipalities & Services | 2006 | 1 | $118,110 |
| Correctional Services | Government of Ontario – Ministries | 2001 | 43 | $114,613 |
| COSTA - IIAS Immigrant Services | Other Public Sector Employers | 2002 | 1 | $122,694 |
| Costi - IIAS | Other Public Sector Employers | 2001 | 1 | $121,292 |
| Costi Immigrant Services | Other Public Sector Employers | 2025 | 24 | $125,160 |
| COSTI-IIAS Immigrant Services | Other Public Sector Employers | 2004 | 1 | $132,891 |
| COTA | Other Public Sector Employers | 2003 | 5 | $120,517 |
| Cota Health | Other Public Sector Employers | 2025 | 9 | $131,146 |
| Cottage Country Family Health Team | Other Public Sector Employers | 2023 | 6 | $126,468 |
| Cou Holding Association Inc (OPAS) | Other Public Sector Employers | 2018 | 23 | $150,779 |
| COU Holding Association Inc. | Other Public Sector Employers | 2016 | 18 | $164,556 |
| Couchiching Family Health Team | Other Public Sector Employers | 2023 | 6 | $119,767 |
| Couchiching First Nation | Other Public Sector Employers | 2025 | 3 | $126,373 |
| Council for Business & the Arts in Canada | Other Public Sector Employers | 2011 | 1 | $111,667 |
| Council of Academic Hospitals of Ontario | Other Public Sector Employers | 2017 | 4 | $134,833 |
| Council of Agencies Serving South Asians | Other Public Sector Employers | 2023 | 1 | $115,000 |
| Council of Regents | Crown Agencies | 2000 | 1 | $104,201 |
| Counselling and Family Service Ottawa | Other Public Sector Employers | 2025 | 1 | $125,000 |
| Counselling Centre of East Algoma | Other Public Sector Employers | 2025 | 1 | $100,289 |
| Counselling Services of Belleville and District | Other Public Sector Employers | 2022 | 2 | $104,228 |
| Country Roads CHC | Other Public Sector Employers | 2002 | 1 | $123,123 |
| Country Roads Comm. Health Centre | Other Public Sector Employers | 1998 | 2 | $123,113 |
| Country Roads Community Health Centre | Other Public Sector Employers | 2025 | 11 | $179,295 |
| Country Roads Community Hlth Ctr. | Other Public Sector Employers | 2001 | 1 | $123,123 |
| Country Roads Community Hlth. Center | Other Public Sector Employers | 2004 | 1 | $145,872 |
| Country Roads Health Centre | Other Public Sector Employers | 1999 | 1 | $123,123 |
| County of Brant | Municipalities & Services | 2025 | 162 | $126,763 |
| County of Bruce | Municipalities & Services | 2025 | 150 | $127,852 |
| County of Bruce General Hospital | Hospitals & Boards of Public Health | 1996 | 1 | $105,555 |
| County of Dufferin | Municipalities & Services | 2025 | 77 | $123,680 |
| County of Elgin | Municipalities & Services | 2025 | 40 | $137,079 |
| County of Essex | Municipalities & Services | 2025 | 286 | $120,560 |
| County of Essex - Library Board | Municipalities & Services | 2008 | 1 | $104,392 |
| County of Frontenac | Municipalities & Services | 2025 | 142 | $118,897 |
| County of Grey | Municipalities & Services | 2025 | 150 | $121,299 |
| County of Haldimand | Municipalities & Services | 2005 | 4 | $119,646 |
| County of Haliburton | Municipalities & Services | 2025 | 35 | $126,791 |
| County of Hasting | Municipalities & Services | 2002 | 1 | $110,099 |
| County of Hastings | Municipalities & Services | 2025 | 151 | $121,899 |
| County of Huron | Municipalities & Services | 2025 | 110 | $122,044 |
| County of Lambton | Municipalities & Services | 2025 | 189 | $123,874 |
| County of Lambton Community Development Corporation | Other Public Sector Employers | 2009 | 1 | $120,216 |
| County of Lanark | Municipalities & Services | 2025 | 36 | $127,858 |
| County of Lanark (Lanark Lodge) | Other Public Sector Employers | 2017 | 7 | $119,499 |
| County of Lennox and Addington | Municipalities & Services | 2025 | 64 | $119,512 |
| County of Middlesex | Municipalities & Services | 2025 | 57 | $146,334 |
| County of Middlesex - Library | Municipalities & Services | 2010 | 1 | $111,756 |
| County of Middlesex – Middlesex London Emergency Medical Services Authority | Municipalities & Services | 2025 | 173 | $114,835 |
| County of Northumberland | Municipalities & Services | 2025 | 148 | $124,619 |
| County of Oxford | Municipalities & Services | 2025 | 207 | $120,886 |
| County of Oxford - Comm. Police Srvcs Board | Municipalities & Services | 2003 | 1 | $106,325 |
| County of Perth | Municipalities & Services | 2025 | 86 | $116,325 |
| County of Peterborough | Municipalities & Services | 2025 | 127 | $125,241 |
| County of Prince Edward | Municipalities & Services | 2025 | 92 | $129,779 |
| County of Renfrew | Municipalities & Services | 2025 | 202 | $125,195 |
| County of Simcoe | Municipalities & Services | 2025 | 584 | $122,077 |
| County of Wellington | Municipalities & Services | 2025 | 155 | $131,448 |
| County Prince Edward | Municipalities & Services | 2001 | 1 | $108,333 |
| County Roads CHC | Other Public Sector Employers | 2005 | 2 | $135,610 |
| County Roads Community Health Centre | Other Public Sector Employers | 1996 | 1 | $131,094 |
| Covent Garden | Municipalities & Services | 2010 | 1 | $110,403 |
| Covent Garden Market | Municipalities & Services | 2011 | 1 | $112,417 |
| Covent Garden Market Corporation | Municipalities & Services | 2009 | 1 | $104,773 |
| CPAC | Other Public Sector Employers | 2021 | 1 | $101,780 |
| Craigwiel Gardens Inc | Other Public Sector Employers | 2025 | 4 | $119,185 |
| Craigwood Youth Services | Other Public Sector Employers | 2024 | 2 | $149,139 |
| Credit Valley Conservation Authority | Other Public Sector Employers | 2025 | 67 | $128,761 |
| Credit Valley Family Health Team | Other Public Sector Employers | 2023 | 3 | $131,028 |
| Credit Valley Hospital | Hospitals & Boards of Public Health | 2010 | 85 | $139,921 |
| Creighton Youth Services | Other Public Sector Employers | 2016 | 1 | $104,924 |
| Crest Support Services (Meadowcrest) Inc | Other Public Sector Employers | 2025 | 3 | $127,741 |
| CRESTech | Other Public Sector Employers | 2002 | 4 | $108,857 |
| Criminal Injuries Compensation Board | Crown Agencies | 2021 | 3 | $114,097 |