| Ontario Heritage Foundation | Crown Agencies | 2004 | 2 | $115,897 |
| Ontario Heritage Trust | Crown Agencies | 2025 | 27 | $139,335 |
| Ontario Highway Transport Board | Crown Agencies | 2020 | 1 | $117,730 |
| Ontario HIV Treatment Network | Other Public Sector Employers | 2025 | 9 | $128,363 |
| Ontario Home Builders Association | Other Public Sector Employers | 2025 | 8 | $154,861 |
| Ontario Home Care Association | Other Public Sector Employers | 2024 | 2 | $184,700 |
| Ontario Hospital Association | Other Public Sector Employers | 2025 | 60 | $161,083 |
| Ontario Human Rights Comm. | Crown Agencies | 1999 | 4 | $117,153 |
| Ontario Human Rights Commission | Crown Agencies | 2025 | 23 | $166,724 |
| Ontario Hydro | Crown Agencies | 1998 | 1,412 | $118,034 |
| Ontario Independent Meat Processors | Other Public Sector Employers | 2011 | 1 | $120,000 |
| Ontario Independent Meat Processors Association | Other Public Sector Employers | 2025 | 2 | $132,420 |
| Ontario Industrial and Finishing Skills Centre | Other Public Sector Employers | 2018 | 2 | $109,844 |
| Ontario Infrastructure and Lands Corporation (infrastructure Ontario) | Crown Agencies | 2025 | 687 | $156,767 |
| Ontario Infrastructure Projects Corporation | Crown Agencies | 2010 | 77 | $150,132 |
| Ontario Institute for Cancer Research | Other Public Sector Employers | 2025 | 114 | $154,906 |
| Ontario Institute for Regenerative Medicine | Other Public Sector Employers | 2019 | 4 | $152,122 |
| Ontario International Trade Corp. | Crown Agencies | 1998 | 1 | $116,239 |
| Ontario Labour Relations Board | Crown Agencies | 2025 | 47 | $154,984 |
| Ontario Lacrosse Association | Other Public Sector Employers | 2020 | 1 | $108,000 |
| Ontario Land Tribunal | Crown Agencies | 2025 | 68 | $135,012 |
| Ontario Land Trust Alliance Inc | Other Public Sector Employers | 2025 | 1 | $124,672 |
| Ontario Legal Aid Plan | Other Public Sector Employers | 1998 | 8 | $113,476 |
| Ontario Library Association | Other Public Sector Employers | 2005 | 2 | $160,745 |
| Ontario Library Service | Other Public Sector Employers | 2025 | 5 | $135,524 |
| Ontario Library Service-north | Other Public Sector Employers | 2020 | 1 | $116,062 |
| Ontario Literacy Coalition / La Coalition De L’alphabétisation De L’ontario | Other Public Sector Employers | 2011 | 1 | $107,396 |
| Ontario Long Term Care Association | Other Public Sector Employers | 2021 | 5 | $159,096 |
| Ontario Lottery and Gaming Corporation | Crown Agencies | 2025 | 724 | $139,756 |
| Ontario Lottery Corporation | Crown Agencies | 1999 | 16 | $122,911 |
| Ontario Lung Association | Other Public Sector Employers | 2025 | 7 | $164,219 |
| Ontario Major Junior Hockey League | Other Public Sector Employers | 2022 | 4 | $278,350 |
| Ontario Media Development Corporation | Crown Agencies | 2025 | 37 | $124,270 |
| Ontario Mental Health Foundation | Crown Agencies | 2017 | 1 | $143,767 |
| Ontario Mental Hlth. Foundation | Other Public Sector Employers | 2004 | 1 | $122,812 |
| Ontario Mining Association (oma) | Other Public Sector Employers | 2025 | 5 | $195,368 |
| Ontario Mission of the Deaf Incorporated | Other Public Sector Employers | 2025 | 9 | $122,572 |
| Ontario Multifaith Council | Other Public Sector Employers | 2006 | 1 | $105,355 |
| Ontario Municipal Social Services Association | Other Public Sector Employers | 2016 | 1 | $103,561 |
| Ontario Municipal Social Services Association (omssa) | Other Public Sector Employers | 2013 | 2 | $125,275 |
| Ontario Museum Association | Other Public Sector Employers | 2024 | 1 | $107,843 |
| Ontario Native Welfare Administrator's Association | Other Public Sector Employers | 2025 | 1 | $128,419 |
| Ontario Native Women's Association | Other Public Sector Employers | 2025 | 9 | $119,850 |
| Ontario Neurotrauma Foundation | Other Public Sector Employers | 2020 | 4 | $135,590 |
| Ontario Northland | Crown Agencies | 1996 | 4 | $114,822 |
| Ontario Northland Transport. Comm. | Crown Agencies | 2002 | 14 | $110,302 |
| Ontario Northland Transportation Commission | Crown Agencies | 2025 | 338 | $129,663 |
| Ontario One Call | Other Public Sector Employers | 2025 | 17 | $159,461 |
| Ontario Online Learning Consortium | Other Public Sector Employers | 2025 | 10 | $146,973 |
| Ontario Parole & Earned Release Board | Crown Agencies | 2007 | 1 | $157,257 |
| Ontario Parole and Earned Release Board | Crown Agencies | 2006 | 1 | $100,236 |
| Ontario Parole Board | Crown Agencies | 2023 | 6 | $132,139 |
| Ontario Physical & Hlth. Ed. Assoc'n. | Other Public Sector Employers | 2004 | 1 | $110,049 |
| Ontario Physical and Health Education Association | Other Public Sector Employers | 2025 | 5 | $137,534 |
| Ontario Physician Services Inc | Other Public Sector Employers | 2023 | 1 | $245,000 |
| Ontario Pipe Trades Council | Other Public Sector Employers | 2022 | 7 | $135,934 |
| Ontario Place | Crown Agencies | 2023 | 1 | $103,749 |
| Ontario Pork Producer's Marketing Board | Other Public Sector Employers | 2014 | 5 | $126,218 |
| Ontario Power Authority | Other Public Sector Employers | 2014 | 83 | $151,585 |
| Ontario Power Generation | Ontario Power Generation | 2025 | 10,346 | $170,202 |
| Ontario Private Campground Association | Other Public Sector Employers | 2023 | 1 | $124,298 |
| Ontario Problem Gambling Research Centre | Other Public Sector Employers | 2014 | 1 | $130,069 |
| Ontario Problem Gambling Research Ctr. | Other Public Sector Employers | 2005 | 1 | $134,931 |
| Ontario Provincial Police | Government of Ontario – Ministries | 2025 | 7,684 | $157,496 |
| Ontario Psychological Association | Other Public Sector Employers | 2023 | 1 | $160,000 |
| Ontario Public Health Association | Other Public Sector Employers | 2017 | 1 | $114,533 |
| Ontario Public School Boards / Conseils Scolaires Association | Other Public Sector Employers | 2017 | 3 | $129,782 |
| Ontario Public School Boards Association | Other Public Sector Employers | 2025 | 7 | $159,714 |
| Ontario Public Service Pension Board (ontario Pension Board) | Crown Agencies | 2025 | 125 | $167,949 |
| Ontario Public Service Quarter Century Club | Other Public Sector Employers | 2022 | 1 | $136,422 |
| Ontario Racing Commission | Crown Agencies | 2016 | 1 | $146,442 |
| Ontario Realty Corporation | Crown Agencies | 2010 | 122 | $132,453 |
| Ontario Rental Housing Tribunal | Crown Agencies | 2006 | 3 | $113,834 |
| Ontario Restaurant Hotel and Motel Association | Other Public Sector Employers | 2023 | 1 | $224,400 |
| Ontario Retirement Communities Association | Other Public Sector Employers | 2023 | 5 | $197,361 |
| Ontario Review Board | Crown Agencies | 2025 | 7 | $129,011 |
| Ontario Rugger Union (o/a Rugby Ontario) | Other Public Sector Employers | 2025 | 1 | $177,629 |
| Ontario Sailing | Other Public Sector Employers | 2013 | 1 | $105,462 |
| Ontario Sailing Association | Other Public Sector Employers | 2025 | 1 | $120,000 |
| Ontario School Bus Association | Other Public Sector Employers | 2021 | 1 | $151,410 |
| Ontario Science Centre | Crown Agencies | 2025 | 58 | $132,152 |
| Ontario Securities Commission | Crown Agencies | 2025 | 528 | $185,266 |
| Ontario Sheep Marketing Agency | Other Public Sector Employers | 2021 | 1 | $117,564 |
| Ontario Sheet Metal Workers Training Centre | Other Public Sector Employers | 2016 | 2 | $120,099 |
| Ontario Shores Centre for Mental Health Sciences | Hospitals & Boards of Public Health | 2025 | 450 | $130,417 |
| Ontario Society for Crippled Children (easter Seals Ont) | Other Public Sector Employers | 2025 | 3 | $144,267 |
| Ontario Society for the Prevention of Cruelty to Animals (spca) | Other Public Sector Employers | 2019 | 10 | $144,539 |
| Ontario Society of Professional Engineers | Other Public Sector Employers | 2022 | 3 | $186,065 |
| Ontario Soil and Crop Improvement Association | Other Public Sector Employers | 2025 | 8 | $165,572 |
| Ontario Stone, Sand & Gravel Association | Other Public Sector Employers | 2022 | 2 | $191,177 |
| Ontario Strategic Infrastructure Financing Authority | Crown Agencies | 2006 | 2 | $133,021 |
| Ontario Streams | Other Public Sector Employers | 2023 | 1 | $115,272 |
| Ontario Stroke Network | Other Public Sector Employers | 2012 | 1 | $133,629 |
| Ontario Superbuild Corp. | Crown Agencies | 2002 | 8 | $165,590 |
| Ontario Tech University | Universities | 2025 | 478 | $152,301 |
| Ontario Telemedicine Network | Other Public Sector Employers | 2019 | 83 | $145,115 |
| Ontario Tender Fruit Growers | Other Public Sector Employers | 2020 | 1 | $114,407 |
| Ontario Tennis Association | Other Public Sector Employers | 2024 | 2 | $154,390 |
| Ontario Tourism Education Corp | Other Public Sector Employers | 2024 | 3 | $143,691 |
| Ontario Tourism Marketing Partnership Corporation | Crown Agencies | 2025 | 39 | $137,181 |