# List of corporate groups and holding companies in Ontario

Tamtam tracks 117 corporate groups and holding companies headquartered in Ontario. This list ranks the 50 largest by number of employees on LinkedIn, led by Barrick Mining Corporation, Cineplex and Extendicare. Their median headcount is 1,614. Half of them were founded in 1973 or later. The most common headquarters are Toronto (22), Markham (8) and Mississauga (6).

These are corporate groups and holding companies in Ontario. The list includes large enterprises like Barrick Mining Corporation, which focuses on gold and copper assets, and Cineplex, an entertainment company operating in film exhibition and other venues. Also present are Extendicare, a provider of senior care services, and Aviva Canada, an insurance provider. This selection primarily features established companies with significant employee bases.

A notable pattern among these companies is their diverse industry representation, ranging from manufacturing and financial services to entertainment and healthcare. While many are headquartered in Toronto, other cities like Markham, Vaughan, and Oakville also host major corporate offices, indicating a spread of corporate activity across Ontario.

🇨🇦 Ontario · 50 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Barrick Mining Corporation](https://www.tamtam.ai/c/barrick-mining-corporation) (barrick.com)<br>A company focused on owning high-quality gold and copper assets, managed by top talent to provide strong returns and benefits to stakeholders | Mining | 🇨🇦 Toronto | 15,486 | 1983 |
| 2 | [Cineplex](https://www.tamtam.ai/c/cineplex) (cineplex.com)<br>A Canadian entertainment company operating in film exhibitor, digital commerce, food service, media, and entertainment venues, including The Rec Room and Playdium | Entertainment Providers | 🇨🇦 Toronto | 6,073 |  |
| 3 | [Extendicare](https://www.tamtam.ai/c/extendicare) (extendicare.com)<br>A leading provider of senior care services in Canada, offering skilled nursing care, home health care, retirement living, and management services with a focus on quality, compassion, and excellence | Hospitals and Health Care | 🇨🇦 Markham | 5,980 | 1968 |
| 4 | [Aviva Canada](https://www.tamtam.ai/c/aviva-canada) (aviva.ca)<br>Leading provider of home, automobile, lifestyle, and business insurance serving 2.5 million customers across Canada with strong financial backing. | Insurance | 🇨🇦 Markham | 5,075 | 1835 |
| 5 | [Definity](https://www.tamtam.ai/c/definity) (definityfinancial.com)<br>Parent company of several established Canadian property and casualty insurance brands focused on improving insurance for customers and communities. | Insurance | 🇨🇦 Waterloo | 4,398 |  |
| 6 | [Recipe Unlimited Corporation](https://www.tamtam.ai/c/recipe-unlimited-corporation) (recipeunlimited.com)<br>Leader in Canada's full-service restaurant industry since 1883, franchising and operating iconic brands nationwide, with a focus on quality dining experiences | Hospitality | 🇨🇦 Vaughan | 4,240 |  |
| 7 | [Perseus Group, Constellation Software](https://www.tamtam.ai/c/perseus-group-constellation-software) (csiperseus.com)<br>The company focuses on nurturing and growing businesses through data-driven guidance, permanent capital, and empowering general managers for maximum potential | Software Development | 🇨🇦 Markham | 3,916 | 2004 |
| 8 | [CSA Testing & Certification](https://www.tamtam.ai/c/csa-testing-and-certification) (csagroup.org)<br>Development of safety and technical standards combined with global testing, inspection, and certification services for diverse industries. | Public Safety | 🇨🇦 Toronto | 3,522 | 1919 |
| 9 | [Samuel, Son & Co.](https://www.tamtam.ai/c/samuel-son-and-co) (samuel.com)<br>Family-owned integrated network providing metal manufacturing, processing, distribution, and value-added industrial products and services across North America. | Manufacturing | 🇨🇦 Oakville | 3,036 | 1855 |
| 10 | [goeasy Ltd.](https://www.tamtam.ai/c/goeasy-ltd) (goeasy.com)<br>A Canadian financial services company providing non-prime leasing, lending, and credit access to millions of Canadians while prioritizing employee culture and community initiatives | Consumer Services | 🇨🇦 Mississauga | 3,024 |  |
| 11 | [Harris Computer](https://www.tamtam.ai/c/harris-computer) (harriscomputer.com)<br>Provides mission-critical software solutions for public sector, healthcare, utilities, and private sectors across North America, Europe, Asia, Australia. | Software Development | 🇨🇦 Ottawa | 2,929 | 1976 |
| 12 | [Multimatic](https://www.tamtam.ai/c/multimatic) (multimatic.com)<br>A global enterprise specializing in supplying automotive components, systems, and engineering services with manufacturing divisions and engineering facilities worldwide | Motor Vehicle Manufacturing | 🇨🇦 Markham | 2,598 | 1984 |
| 13 | [TMX Group](https://www.tamtam.ai/c/tmx-group) (tmx.com)<br>Operate global capital and commodity markets, providing technology-driven solutions for businesses, investors, and traders to raise capital and prosper. | Financial Services | 🇨🇦 Toronto | 2,564 |  |
| 14 | [Longo's](https://www.tamtam.ai/c/longo-s) (longos.com)<br>Specializing in providing the best food experience in the Canadian grocery industry, with a focus on trustworthiness, honesty, and community involvement | Retail | 🇨🇦 Vaughan | 2,286 | 1956 |
| 15 | [Pizza Pizza Limited](https://www.tamtam.ai/c/pizza-pizza-limited) (pizzapizza.ca)<br>Canadian pizza pioneer with over 750 locations, offering quality food, diverse menus, and exciting promotions with a focus on innovation and community involvement | Food and Beverage Services | 🇨🇦 Toronto | 2,267 | 1967 |
| 16 | [Flynn Group of Companies](https://www.tamtam.ai/c/flynn-group-of-companies) (flynncompanies.com)<br>Leading North American building envelope contractor offering roofing, glazing, metals, waterproofing services Seeking to merge with like-minded companies for growth opportunities | Construction | 🇨🇦 Mississauga | 2,229 | 1978 |
| 17 | [Momentum Financial Services Group](https://www.tamtam.ai/c/momentum-financial-services-group) (mfsg.com)<br>Provides short-term loans, money transfers, prepaid cards, and technology solutions to underserved communities for accessible financial services. | Financial Services | 🇨🇦 Toronto | 2,045 |  |
| 18 | [Sofina Foods Canada](https://www.tamtam.ai/c/sofina-foods-canada) (sofinafoods.com)<br>Leading manufacturer and supplier of pork, beef, fish, turkey, and chicken products for retail and foodservice markets globally. | Food and Beverage Manufacturing | 🇨🇦 Markham | 1,977 | 1995 |
| 19 | [Northbridge Financial Corporation](https://www.tamtam.ai/c/northbridge-financial-corporation) (careers.nbfc.com)<br>A leading Canadian commercial property and casualty insurance group offering innovative solutions to protect businesses and support communities nationwide for 100 years | Insurance | 🇨🇦 Toronto | 1,956 |  |
| 20 | [Canada Cartage](https://www.tamtam.ai/c/canada-cartage) (canadacartage.com)<br>Providing customer-located, dedicated trucking and warehouse services with fleets and drivers residing at client locations across Canada. | Truck Transportation | 🇨🇦 Mississauga | 1,846 | 1914 |
| 21 | [Questrade Financial Group](https://www.tamtam.ai/c/questrade-financial-group) (questrade.com)<br>A Canadian financial services company offering low-cost digital alternatives, investment opportunities, online wealth management, and a forward-thinking workplace culture | Financial Services | 🇨🇦 Toronto | 1,805 |  |
| 22 | [Foresters Financial](https://www.tamtam.ai/c/foresters-financial) (foresters.com)<br>It redefines life insurance and savings with digitized processes, member benefits, and tailored plans for improved financial security and wellness. | Financial Services | 🇨🇦 Toronto | 1,658 | 1874 |
| 23 | [Sonepar Canada](https://www.tamtam.ai/c/sonepar-canada) (soneparcanada.com)<br>A leading distributor of electrical products with a strong presence in Canada, represented by multiple brands and over 1800 employees | Wholesale | 🇨🇦 Brampton | 1,634 |  |
| 24 | [Oxford Properties Group](https://www.tamtam.ai/c/oxford-properties-group) (oxfordproperties.com)<br>Global real estate investor, developer, and manager across various property types including office, life science, industrial, retail, living, and hotels. | Real Estate | 🇨🇦 Toronto | 1,627 | 1960 |
| 25 | [Ross Video](https://www.tamtam.ai/c/ross-video) (rossvideo.com)<br>Designs and manufactures innovative live production equipment used globally by broadcasters, sports venues, government, and production companies. | Broadcast Media Production and Distribution | 🇨🇦 Iroquois | 1,614 | 1973 |
| 26 | [MBI Brands](https://www.tamtam.ai/c/mbi-brands) (mbibrands.com)<br>A leading Canadian franchisor operating premium QSR brands, with nearly 300 restaurants and plans for further expansion | Food and Beverage Retail | 🇨🇦 Markham | 1,396 |  |
| 27 | [Economical Insurance](https://www.tamtam.ai/c/economical-insurance) (economical.com)<br>Provides insurance solutions for homes, vehicles, farms, and commercial operations with a focus on customer care and innovation. | Insurance | 🇨🇦 Waterloo | 1,391 |  |
| 28 | [KAR GROUP LLC](https://www.tamtam.ai/c/kar-group-llc) (kar-group.com)<br>A diversified group of market leading businesses in construction, engineering, property, trading, performance cars, travel, leisure, and equestrian industries | Aviation and Aerospace Component Manufacturing | 🇨🇦 Toronto | 1,213 | 1860 |
| 29 | [Drake International](https://www.tamtam.ai/c/drake-international) (drakeintl.com)<br>A global leader in flexible and permanent staffing, offering talent management solutions to maximize human capital assets and increase organizational bottom line | Human Resources Services | 🇨🇦 Toronto | 1,189 | 1951 |
| 30 | [Morguard](https://www.tamtam.ai/c/morguard) (morguard.com)<br>Fully integrated real estate business owning, managing, and investing in diverse assets across North America, including REITs and providing advisory services | Real Estate | 🇨🇦 Mississauga | 1,123 | 1975 |
| 31 | [Volaris Group](https://www.tamtam.ai/c/volaris-group) (volarisgroup.com)<br>Acquires and grows vertical market technology companies through best practice sharing, organic initiatives, and long-term sustainable development. | Software Development | 🇨🇦 Mississauga | 1,102 |  |
| 32 | [Sunwing](https://www.tamtam.ai/c/sunwing) (sunwing.ca)<br>A group of leading vacation brands in North America offering leisure tours, travel retail services, and destination wedding planning | Travel Arrangements | 🇨🇦 Toronto | 1,077 | 2002 |
| 33 | [Atlantic Packaging Products Ltd.](https://www.tamtam.ai/c/atlantic-packaging-products-ltd) (atlantic.ca)<br>Design manufacture and deliver innovative corrugated packaging products with integrated solutions including pre-print, retail displays, supply chain, and recycled materials across Canada and US. | Packaging and Containers Manufacturing | 🇨🇦 Scarborough | 1,048 |  |
| 34 | [Votorantim Cimentos North America (VCNA)](https://www.tamtam.ai/c/votorantim-cimentos-north-america-vcna) (votorantimcimentos.com)<br>Leading provider of cement, concrete and aggregates in North America, part of a global building materials and sustainability solutions provider | Wholesale Building Materials | 🇨🇦 Toronto | 1,044 | 2001 |
| 35 | [Connor, Clark & Lunn Financial Group (CC&L)](https://www.tamtam.ai/c/connor-clark-and-lunn-financial-group-cc-and-l) (cclfg.cclgroup.com)<br>Multi-boutique asset management firm offering a diverse range of investment solutions for institutions, individuals, and financial advisors in Canada | Financial Services | 🇨🇦 Toronto | 963 | 2003 |
| 36 | [Dye & Durham Corporation](https://www.tamtam.ai/c/dye-and-durham-corporation) (dyedurham.com)<br>Provider of practice management solutions for legal professionals, data insights for corporate transactions, and payments infrastructure for government and financial institutions across multiple countries | Software Development | 🇨🇦 Toronto | 945 |  |
| 37 | [Cementation Americas](https://www.tamtam.ai/c/cementation-americas) (cementation.com)<br>Global mining services provider focused on underground mine contracting, engineering, and material handling solutions, committed to safety, value, and client satisfaction | Mining | 🇨🇦 North Bay | 933 | 1998 |
| 38 | [Dream](https://www.tamtam.ai/c/dream) (dream.ca)<br>Real estate asset manager, owner, and developer with over $23 billion in assets under management, revolutionizing the way people live and work | Real Estate | 🇨🇦 Toronto | 903 | 1994 |
| 39 | [Russel Metals](https://www.tamtam.ai/c/russel-metals) (russelmetals.com)<br>A leading metal distributor in North America with a focus on value-added processing, serving various industries with a wide range of metal products | Manufacturing | 🇨🇦 Mississauga | 850 | 1784 |
| 40 | [Marsh Canada](https://www.tamtam.ai/c/marsh-canada) (corporate.marsh.com)<br>Global leader in insurance brokering and risk advisory services, providing data-driven solutions to commercial and individual clients worldwide through multiple market-leading businesses | Insurance | 🇨🇦 Toronto | 839 | 1914 |
| 41 | [CCL Industries](https://www.tamtam.ai/c/ccl-industries)<br>Manufacturing labels, specialty media, digital printing software, aluminum aerosol cans, plastic tubes, instructional leaflets, and precision metal components for various markets. | Packaging and Containers Manufacturing | 🇨🇦 Toronto | 835 | 1951 |
| 42 | [Giampaolo Group Inc.](https://www.tamtam.ai/c/giampaolo-group-inc)<br>Fully integrated metal management company with operations in metal recycling, steel processing, aluminum production, real estate development, and charitable fundraising events for various causes | Mining | 🇨🇦 Brampton | 829 | 1975 |
| 43 | [Glencore Zinc](https://www.tamtam.ai/c/glencore-zinc) (glencore.com)<br>Global commodity business with autonomous operations in mining and production of zinc, with interests in copper-zinc mining projects worldwide for growth | Mining & Metals | 🇨🇦 Toronto | 812 | 2002 |
| 44 | [Tucows](https://www.tamtam.ai/c/tucows) (tucows.com)<br>The company focuses on keeping people connected and the internet open through domain services, fiber internet, and telecom software solutions | IT Services and IT Consulting | 🇨🇦 Toronto | 793 |  |
| 45 | [The Miller Group](https://www.tamtam.ai/c/the-miller-group) (millergroup.ca)<br>A leading road construction company in Canada with a long history of excellence, investing in employees, embracing diversity, and offering rewarding careers | Construction | 🇨🇦 Markham | 727 |  |
| 46 | [CAA South Central Ontario](https://www.tamtam.ai/c/caa-south-central-ontario) (caasco.com)<br>Provider of roadside assistance, automotive, insurance, travel, and rewards services, focused on delivering peace of mind and quality service to members | Insurance | 🇨🇦 Thornhill | 705 |  |
| 47 | [Northland Power Inc.](https://www.tamtam.ai/c/northland-power-inc) (northlandpower.com)<br>An independent power producer focused on sustainable infrastructure assets, including natural gas, solar, and wind energy projects for long-term value and environmental impact | Renewable Energy Power Generation | 🇨🇦 Toronto | 692 |  |
| 48 | [Enstar Group](https://www.tamtam.ai/c/enstar-group) (enstargroup.com)<br>Global insurance group specializing in run-off risk management, claims handling, and strategic investments to optimize capital and legacy solutions. | Insurance | 🇨🇦 Hamilton | 689 | 1993 |
| 49 | [Sleeman Breweries Ltd.](https://www.tamtam.ai/c/sleeman-breweries-ltd) (sleemanbreweries.ca)<br>A Canadian brewery with a rich family legacy, producing top craft beers under stringent standards, offering a variety of world-class brands | Food and Beverage Services | 🇨🇦 Guelph | 685 | 1834 |
| 50 | [Miller Waste Systems Inc.](https://www.tamtam.ai/c/miller-waste-systems-inc) (millerwaste.ca)<br>A Canadian waste management leader offering collection, recycling, composting, and hazardous waste solutions while also producing renewable energy and fertilizer | Environmental Services | 🇨🇦 Markham | 683 | 1961 |

## How this list is built

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 Nov 11, 2026.

## More company lists in Ontario

- [The largest companies in Ontario](https://www.tamtam.ai/l/largest-companies-ontario) (5,032)
- [Multinational companies in Ontario](https://www.tamtam.ai/l/multinational-companies-ontario) (901)
- [Financial services firms in Ontario](https://www.tamtam.ai/l/financial-services-firms-ontario) (396)
- [Manufacturers in Ontario](https://www.tamtam.ai/l/manufacturers-ontario) (389)
- [Critical infrastructure operators in Ontario](https://www.tamtam.ai/l/critical-infrastructure-operators-ontario) (344)
- [Retail chains in Ontario](https://www.tamtam.ai/l/retail-chains-ontario) (327)
- [Companies with in-house R&D in Ontario](https://www.tamtam.ai/l/r-and-d-companies-ontario) (300)
- [Logistics companies in Ontario](https://www.tamtam.ai/l/logistics-companies-ontario) (285)
- [Education providers in Ontario](https://www.tamtam.ai/l/education-companies-ontario) (276)
- [SaaS companies in Ontario](https://www.tamtam.ai/l/saas-companies-ontario) (275)
- [Truck Transportation companies in Ontario](https://www.tamtam.ai/l/truck-transportation-companies-ontario) (270)
- [Transportation, Logistics, Supply Chain and Storage companies in Ontario](https://www.tamtam.ai/l/transportation-logistics-supply-chain-and-storage-companies-ontario) (261)
- [Public sector organisations in Ontario](https://www.tamtam.ai/l/public-sector-organisations-ontario) (259)
- [Financial Services companies in Ontario](https://www.tamtam.ai/l/financial-services-companies-ontario) (250)
- [IT Services and IT Consulting companies in Ontario](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-ontario) (235)
- [Software Development companies in Ontario](https://www.tamtam.ai/l/software-development-companies-ontario) (231)
- [Healthcare providers in Ontario](https://www.tamtam.ai/l/healthcare-providers-ontario) (226)
- [Hardware manufacturers in Ontario](https://www.tamtam.ai/l/hardware-companies-ontario) (213)
- [Professional services firms in Ontario](https://www.tamtam.ai/l/professional-services-firms-ontario) (211)
- [Hospitals and Health Care companies in Ontario](https://www.tamtam.ai/l/hospitals-and-health-care-companies-ontario) (205)
- [Distributors and wholesalers in Ontario](https://www.tamtam.ai/l/distributors-and-wholesalers-ontario) (183)
- [Companies with a mobile app in Ontario](https://www.tamtam.ai/l/companies-with-mobile-app-ontario) (181)
- [Publicly traded companies in Ontario](https://www.tamtam.ai/l/publicly-traded-companies-ontario) (156)
- [IT services companies in Ontario](https://www.tamtam.ai/l/it-services-companies-ontario) (156)

## The same list elsewhere in Canada

- [Corporate groups and holding companies in Canada](https://www.tamtam.ai/l/holding-companies-canada) (318)
- [Corporate groups and holding companies in the province of Quebec](https://www.tamtam.ai/l/holding-companies-province-of-quebec) (75)
- [Corporate groups and holding companies in Alberta](https://www.tamtam.ai/l/holding-companies-alberta) (50)
- [Corporate groups and holding companies in British Columbia](https://www.tamtam.ai/l/holding-companies-british-columbia) (33)
- [Corporate groups and holding companies in Toronto](https://www.tamtam.ai/l/holding-companies-toronto) (48)
- [Corporate groups and holding companies in Montreal](https://www.tamtam.ai/l/holding-companies-montreal) (39)

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Source: https://www.tamtam.ai/l/holding-companies-ontario