| # | Company | Employees |
|---|---|---|
| 1 |
University of Torontodefygravitycampaign.utoronto.ca
Leading Canadian university focused on research, innovation, and global education to address pressing societal challenges and prepare students for success |
28,832 |
| 2 |
Canada Post / Postes Canadacanadapost-postescanada.ca
Nationwide postal service with extensive retail network, delivering parcels and mail to over 17 million Canadian addresses. |
23,941 |
| 3 |
City of Torontotoronto.ca
Provides diverse public services to residents, businesses, and visitors, encompassing technology, finance, culture, and innovation, employing a large workforce across numerous divisions. |
23,495 |
| 4 |
Canadian Armed Forces | Forces armées canadiennesforces.ca
Offering over 100 trades, the organization provides world-class qualifications, competitive salaries, benefits, stability, and exciting opportunities for travel, adventure, and making a difference |
20,412 |
| 5 |
CBC/Radio-Canadacbc.radio-canada.ca
Canadian public broadcaster promoting Canadian culture through diverse programming in multiple languages, supporting creative work and job opportunities in television production |
14,336 |
| 6 |
McMaster Universitymcmaster.ca
Leading Canadian university known for innovation in education and research, serving 30,000 students and a global alumni network. |
13,160 |
| 7 |
University Health Networkuhn.ca
Largest Canadian research hospital network specializing in patient care, medical research, education, and fundraising for advanced healthcare services. |
11,930 |
| 8 |
Toronto District School Boardtdsb.on.ca
Serving over 239,000 students and 100,000 adult learners across 582 schools, focusing on academic performance and community support. |
11,719 |
| 9 |
University of Waterloouwaterloo.ca
Leader in innovation driving economic and social prosperity through talent pipeline, groundbreaking research, entrepreneurial culture, and industry collaboration for student success |
11,390 |
| 10 |
York Universityyorku.ca
Educates students, fosters career advancement, and drives positive societal change through research and community engagement. |
11,154 |
| 11 |
Peel District School Boardpeelschools.org
A large organization in Peel serving over 156,000 students in K-12 with a focus on inspiring success, confidence, and hope through various programs and support services |
10,571 |
| 12 |
Queen's Universityqueensu.ca
A prestigious university known for its research, innovation, and commitment to addressing global challenges through scholarship and international engagement |
9,891 |
| 13 |
Ontario Power Generationopg.com
Leading clean power generator advancing clean energy innovations, striving for a net-zero future with diverse electricity generation fleet in Ontario and the United States |
9,878 |
| 14 |
City of Ottawa / Ville d’Ottawajobs-emplois.ottawa.ca
A diverse workforce providing essential programs and services for over one million residents in Ottawa, with a focus on customer service and community well-being |
9,194 |
| 15 |
Toronto Transit Commission (TTC)ttc.ca
A leading transit system in Toronto, providing safe and reliable transportation to over 17 million customers daily through various modes |
8,829 |
| 16 |
Health Canada | Santé Canadahealth.canada.ca
A Federal department in Canada focused on improving health for individuals through recruitment of professionals in various fields and student programs |
8,686 |
| 17 |
Toronto Metropolitan Universitytorontomu.ca
Innovative urban university in Toronto, focusing on creativity, entrepreneurship, inclusivity, and global community engagement to serve societal needs |
8,478 |
| 18 |
University of Guelphuoguelph.ca
Dedicated to improving quality of life through innovative research and education in essential areas like water, food, health, and environment |
7,725 |
| 19 |
The Ottawa Hospitalottawahospital.on.ca
Innovative teaching and research hospital providing specialized care, developing new treatments, and improving patient care through community engagement and global impact |
7,679 |
| 20 |
Sunnybrooksunnybrook.ca
A leading teaching hospital affiliated with the University of Toronto, specializing in patient care, groundbreaking research, and inventing the future of healthcare |
7,599 |
| 21 |
London Health Sciences Centre (LHSC)lhsc.on.ca
Acute care teaching hospital offering specialized clinical services, leading in discovery and innovation, providing exceptional patient care and training healthcare professionals |
7,092 |
| 22 |
Carleton Universitycarleton.ca
University located near government and high tech companies, combining research and teaching to provide superior education and solve real problems. |
6,886 |
| 23 |
Ottawa-Carleton District School Board (OCDSB)ocdsb.ca
A large school board in Eastern Ontario offering a wide range of programs to support students in academics, arts, athletics, and technology |
6,863 |
| 24 | 6,848 | |
| 25 |
Seneca Polytechnicsenecapolytechnic.ca
Innovative, daring organization encouraging advancement and leadership in polytechnic education |
6,721 |
| 26 |
Hamilton Health Scienceshamiltonhealthsciences.ca
Healthcare organization delivering specialized cardiac, stroke, trauma, cancer, palliative, and pediatric care to southwestern Ontario and beyond. |
6,690 |
| 27 |
Toronto Catholic District School Boardtcdsb.org
A leading Catholic school board in Toronto providing educational excellence rooted in Gospel values to over 84,000 students across 195 schools |
6,590 |
| 28 |
Metrolinxmetrolinx.com
Provincial agency managing regional transportation through GO Transit, UP Express, and PRESTO while executing the largest transit infrastructure expansion in Ontario history. |
6,444 |
| 29 |
Agriculture and Agri-Food Canada/ Agriculture et Agroalimentaire Canadaagriculture.canada.ca
Agriculture and agri-food company supporting farmers and food producers in growth and development Terms of use: http://owly/gnCW50FjUsI / http://owly/XHSU50FjUvL |
6,405 |
| 30 |
Trillium Health Partnersthp.ca
Leading hospital providing full range of acute care services, specialized programs, and community-based care Committed to delivering high-quality, accessible patient care |
6,009 |
| 31 |
Statistics Canada | Statistique Canadastatcan.gc.ca
A leading statistical agency providing relevant, accurate, and timely data to help Canadians better understand their country through an app and podcast series |
5,917 |
| 32 | 5,666 | |
| 33 |
Fisheries and Oceans Canada / Pêches et Océans Canadadfo-mpo.gc.ca
Manage fisheries and aquaculture sustainably, protect aquatic ecosystems, maintain navigable waterways, and respond to maritime emergencies with Indigenous collaboration. |
5,665 |
| 34 |
Correctional Service Canada │ Service correctionnel Canadacsc-scc.gc.ca
Administer federal prison sentences, manage institutions with various security levels, and supervise offenders under conditional release in communities. |
5,587 |
| 35 |
Transport Canada - Transports Canadatc.canada.ca
A department with 5000 employees nationwide seeks individuals to contribute to meaningful work, growth opportunities, attractive benefits, and inclusive work environment |
5,540 |
| 36 |
George Brown Polytechnicgeorgebrown.ca
Leading college in Toronto with industry connections, offering real-world experience through diverse programs for full and part-time students Visit website for details |
5,381 |
| 37 |
Humber Collegehumber.ca
Provides diverse full-time, part-time, and online programs focused on career readiness, serving thousands of students with quality teaching. |
5,249 |
| 38 |
Conestoga Collegeconestogac.on.ca
career-focused education, training, applied research, technology-enhanced learning, co-op opportunities, and comprehensive student support for diverse learners. |
5,198 |
| 39 |
Shared Services Canada | Services partagés Canadacanada.ca
Modernizing Government of Canada's IT infrastructure by delivering email, data centre, telecommunication, videoconferencing, and Wi-Fi services to customers |
5,161 |
| 40 |
Sheridan Collegesheridancollege.ca
Established in 1967, this institution has grown to become a leading Ontario postsecondary institution with four campuses and a diverse range of programs |
5,079 |
| 41 |
Centennial Collegecentennialcollege.ca
Leading Ontario community college with diverse campus locations, offering innovative programs, exemplary teaching, and extensive partnership building since 1966 |
5,076 |
| 42 |
Algonquin College of Applied Arts and Technologyalgonquincollege.com
Leading college in eastern Ontario offering diverse hands-on learning programs, including degrees, diplomas, and certificates, with a strong focus on student success and innovation |
4,972 |
| 43 |
St. Michael's Hospitalunityhealth.to
A leading hospital providing compassionate care, medical education in 27 disciplines, and research through the Keenan Research Centre for global impact |
4,868 |
| 44 |
Durham District School Boardddsb.ca
A public education board in rural and urban communities, providing educational services to over 79,000 regular day students in 135 schools |
4,721 |
| 45 |
Waterloo Region District School Boardwrdsb.ca
A large school board in Ontario providing education for approximately 62,000 students from kindergarten to grade 12, with a focus on student success and community involvement |
4,717 |
| 46 |
City Of Hamiltonhamilton.ca
The organization aims to provide high-quality public services for a healthy, safe, and prosperous community while fostering collective ownership and diversity |
4,633 |
| 47 |
Ottawa Catholic School Boardocsb.ca
Providing faith-based, inclusive education with English and French programs, fostering critical thinking, creativity, well-being, and community connections. |
4,559 |
| 48 | 4,477 | |
| 49 |
Fanshawe Collegefanshawec.ca
A large college in Ontario offering diploma, degree, certificate, and apprenticeship programs to over 43,000 students annually from 50 countries |
4,454 |
| 50 |
Canada Border Services Agency | Agence des services frontaliers du Canadacbsa-asfc.gc.ca
Ensures national security and economic prosperity by managing and monitoring international travel and trade at Canada's borders. |
4,369 |
| 51 |
William Osler Health Systemwilliamoslerhs.ca
Health system with three hospitals serving 13 million residents, providing a wide range of services including inpatient, outpatient, urgent care, and specialty clinics |
4,350 |
| 52 |
Halton District School Boardhdsb.ca
Educates 67,000+ students across Southern Ontario, focusing on innovation, collaboration, and staff development in various cities like Burlington and Milton. |
4,292 |
| 53 |
University of Windsoruwindsor.ca
A student-focused university offering undergraduate and graduate programs, professional schools, and innovative research facilities, promoting diversity and excellence in education |
4,284 |
| 54 |
City of Bramptonbrampton.ca
City with diverse cultures and innovative spirit focusing on technology, environmental innovation, and community-driven progress for residents and businesses. |
4,240 |
| 55 |
Workplace Safety and Insurance Board (WSIB)wsib.ca
A provider of insurance, benefits, and support to individuals who suffer work-related injuries or illnesses, helping them return to work |
4,179 |
| 56 |
Dufferin-Peel Catholic District School Boarddpcdsb.org
A large school board in Ontario with over 80,000 students in 151 schools, providing Catholic education and adult learning programs |
4,108 |
| 57 |
Brock Universitybeacons.ai
A top Canadian post-secondary institution offering diverse programs, research opportunities, and experiential learning to students alongside a supportive employment environment |
4,079 |
| 58 |
Wilfrid Laurier Universitywlu.ca
Canadian university focusing on teaching, research, and student satisfaction with programs in arts, business, science, social work, and education. |
4,060 |
| 59 |
Canadian Food Inspection Agencyinspection.canada.ca
A federal regulator in Canada focused on enhancing food safety, animal health, and protecting plant resources with a commitment to employee growth and impact |
4,024 |
| 60 |
Lakeridge Healthlakeridgehealth.on.ca
A comprehensive healthcare provider with multiple hospitals, specialty centers, and community services, committed to delivering high-quality care to the region |
3,760 |
| 61 |
Canadian Blood Servicesblood.ca
Canada's national organization responsible for ensuring a secure and sustainable supply of blood and organs for transfusion and transplantation |
3,745 |
| 62 | 3,487 | |
| 63 |
Hamilton-Wentworth District School Board (HWDSB)hwdsb.on.ca
Empowering students to learn and grow to their full potential in a diverse world through fostering curiosity, creativity, and possibility |
3,452 |
| 64 |
Mohawk Collegemohawkcollege.ca
A leading educational institution in Ontario, offering a wide range of programs to 30,000 students, with a focus on student and graduate satisfaction |
3,267 |
| 65 |
Niagara Healthniagarahealth.on.ca
Regional hospital system providing acute care services, research, and innovation to improve healthcare for residents in the Niagara region |
3,213 |
| 66 |
Durham Collegedurhamcollege.ca
Durham College offers full-time and part-time programs in various disciplines to over 12,000 students, including a new health care technology management degree program |
3,210 |
| 67 |
Mackenzie Healthmackenziehealth.ca
Regional healthcare provider in Southwest York Region with two hospitals and community-based services, offering a wide range of healthcare programs and services to the community |
3,197 |
| 68 |
Ryerson Universitytorontomu.ca
Innovative urban university in downtown Toronto focusing on entrepreneurship, offering over 100 programs to 45,300 students with a commitment to community engagement |
3,137 |
| 69 |
Ontario Health | Santé Ontarioontariohealth.ca
Government agency ensuring high-quality, patient-centred healthcare services across Ontario, promoting health equity and supporting healthcare professionals. |
3,020 |
| 70 |
Conestoga Collegeon.ca
A leader in polytechnic education offering career-focused programs, engineering degrees, and support services while promoting economic prosperity and student success |
2,968 |
| 71 |
Georgian Collegegeorgiancollege.ca
Provider of over 130 market-driven programs including degrees, diplomas, certificates, and apprenticeships, with a focus on co-operative education and graduate employment success |
2,963 |
| 72 |
North York General Hospitalnygh.on.ca
A leading community academic hospital in Canada offering a wide range of acute, ambulatory, and long-term care services with a focus on patient- and family-centered care |
2,917 |
| 73 |
Canadian Coast Guard/Garde côtière canadiennecanada.ca
A federal agency that operates a civilian fleet and provides maritime services to Canadians, ensuring safe waters, environmental protection, and economic growth |
2,892 |
| 74 |
Canada Mortgage and Housing Corporation (CMHC) Société canadienne d'hypothèques et de logement(SCHL)cmhc-schl.gc.ca
Provide housing financing solutions, implement government housing programs, and share research and data to support the housing sector. |
2,887 |
| 75 |
Toronto Police Servicetps.ca
Providing comprehensive police services with a focus on community partnership, innovation, training, and diverse career opportunities for members. |
2,815 |
| 76 |
Kingston Health Sciences Centrekingstonhsc.ca
Top Canadian hospital, advancing health care through patient care, medical research, and training future healthcare professionals for Southeastern Ontario. |
2,793 |
| 77 |
CHEOcheo.on.ca
A global leader in pediatric health care and research, providing excellence in complex care, education, and community partnership for children and youth |
2,784 |
| 78 |
Export Development Canada | Exportation et développement Canadalinktr.ee
Provide financial products, trade knowledge, and support to Canadian businesses for global growth, risk management, and sustainable inclusive trade. |
2,752 |
| 79 |
Niagara Collegeniagaracollege.ca
Leader in applied education and training, established in 1967 in Welland and now expanding across the Niagara region for top student satisfaction |
2,686 |
| 80 |
Simcoe County District School Boardscdsb.on.ca
A large education system in Ontario providing public education to over 50,000 students from Kindergarten to Grade 12, along with adult education services |
2,609 |
| 81 |
Scarborough Health Networkshn.ca
A leading healthcare organization in Scarborough, offering diverse programs and services, including nephrology, cardiac care, spine center, and medical training partnerships with universities |
2,536 |
| 82 |
Bank of Canadabankofcanada.ca
Central bank focused on maintaining low, stable inflation and promoting economic and financial welfare for Canada's overall economic health. |
2,496 |
| 83 |
Ontario Tech Universityontariotechu.ca
Innovative university focusing on advancing knowledge, integrating social and ethical implications of technology, and collaborating on solutions with partners |
2,479 |
| 84 |
Canadian Nuclear Laboratoriescnl.ca
A leading organization in nuclear science and technology, specializing in research, development, engineering, waste management, and decommissioning services for various applications |
2,340 |
| 85 |
Michael Garron Hospitaltehn.ca
A vibrant community hospital in East Toronto providing high-quality, patient-centred healthcare services along the continuum of care with strong partnerships |
2,219 |
| 86 |
Royal Victoria Regional Health Centrervh.on.ca
Healthcare institution in Barrie, Ontario serving over 450,000 residents with specialized services like interventional radiology, stroke care, trauma, cancer, heart, child, and youth programs |
2,191 |
| 87 |
Collège La Citécollegelacite.ca
Discover life in the largest French-speaking college in Ontario Stay informed about job opportunities Dynamic, inclusive environment with top employer rankings Follow on social media for more |
2,069 |
| 88 |
Grand River Hospitalwrhn.ca
Ontario's large community hospital in Kitchener - Waterloo, offering a wide range of medical programs and services with over 6000 team members |
2,058 |
| 89 |
Upper Grand District School Boardugdsb.ca
The organization provides education to over 35,000 students in Guelph, Wellington, and Dufferin, focusing on student success and promoting diversity, equity, and inclusion |
2,050 |
| 90 |
Kawartha Pine Ridge District School Boardkprschools.ca
The company is a school board that values staff, offers leadership opportunities, and serves urban and rural communities with 88 schools |
1,989 |
| 91 |
Oak Valley Healthoakvalleyhealth.ca
A leading Ontario community health care organization with two hospitals and a Reactivation Care Centre, providing high-quality, patient-centered care Funded by community donations |
1,969 |
| 92 |
St. Lawrence Collegestlawrencecollege.ca
A leading community college in Eastern Ontario offering over 100 programs, preparing students for the global economy with practical learning opportunities |
1,921 |
| 93 |
District School Board of Niagaradsbn.org
A network of schools in the Niagara Region providing quality public education to over 39,000 students with a focus on student learning and empowerment |
1,902 |
| 94 |
Toronto Hydrotorontohydro.com
Operate and maintain electricity distribution system serving nearly 793,000 customers, ensuring safe, reliable power supply in Toronto. |
1,861 |
| 95 |
Halton Catholic District School Boardhcdsb.org
A publicly-funded Catholic education system serving over 37,000 students in the Halton Region with a focus on achievement and community |
1,852 |
| 96 |
St. Clair Collegestclaircollege.ca
Post-secondary education institution offering 120+ programs in Health Sciences, Business, Engineering, Media & Arts, with residences for students in Windsor and Chatham |
1,807 |
| 97 |
Toronto Public Librarytpl.ca
A busy urban public library system in Toronto providing access to technology, lifelong learning, diverse cultural experiences, and leisure activities |
1,758 |
| 98 |
Health Sciences North/Horizon Santé-Nordhsnsudbury.ca
An integrated network providing high-quality patient care, research, teaching, and services in various medical specialties to communities in Northern Ontario |
1,755 |
| 99 |
Fleming Collegeflemingcollege.ca
Fleming College offers personalized learning and support in various fields, fostering innovation and sustainability for students, communities, and the environment |
1,746 |
| 100 |
University of Toronto Mississaugautm.utoronto.ca
A well-established academic institution with a diverse range of programs and institutes, serving thousands of students and employing a large staff |
1,732 |
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Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Oct 24, 2026.
More company lists in Ontario
- The largest companies in Ontario 4,330
- Financial services firms in Ontario 315
- Critical infrastructure operators in Ontario 262
- SaaS companies in Ontario 232
- Financial Services companies in Ontario 228
- Retail chains in Ontario 213
- Truck Transportation companies in Ontario 206
- Transportation, Logistics, Supply Chain and Storage companies in Ontario 196
- Hospitals and Health Care companies in Ontario 195
- Software Development companies in Ontario 188
- IT Services and IT Consulting companies in Ontario 179
- Manufacturers in Ontario 169
- Education providers in Ontario 148
- Logistics companies in Ontario 133
- Healthcare providers in Ontario 131
- Government Administration companies in Ontario 128
- Construction companies in Ontario 127
- Insurance companies in Ontario 123
- Contract manufacturers in Ontario 113
- Retail companies in Ontario 113
- Non-profit Organizations companies in Ontario 106
- Higher Education companies in Ontario 102
- Distributors and wholesalers in Ontario 100
- Real Estate companies in Ontario 98
The same list elsewhere in Canada
- Public sector organisations in Canada 499
- Public sector organisations in the province of Quebec 130
- Public sector organisations in British Columbia 59
- Public sector organisations in Alberta 52
- Public sector organisations in Toronto 43
- Public sector organisations in Ottawa 42
- Public sector organisations in Montreal 41
- Public sector organisations in Quebec City 31