# 30 leading companies with in-house R&D in Toronto

Tamtam tracks 93 companies with in-house R&D headquartered in Toronto. This list ranks the 30 largest by number of employees on LinkedIn, led by Thomson Reuters, University of Toronto and Celestica. Their median headcount is 4,059. Half of them were founded in 1974 or later.

These Toronto-based companies with in-house R&D are primarily large organizations, including several major healthcare networks and educational institutions. Among them, Thomson Reuters offers news and information tools for professionals, Celestica provides design and manufacturing solutions for various industries, and Apotex Inc. produces affordable pharmaceutical products. University of Toronto is a leading Canadian university focused on research and education.

A notable pattern among these companies is the strong presence of the healthcare sector, with organizations like University Health Network, Unity Health Toronto, and The Hospital for Sick Children dominating a significant portion of the list. This indicates a concentration of R&D efforts within medical research, patient care innovation, and health technology in Toronto.

🇨🇦 Toronto · 30 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Thomson Reuters](https://www.tamtam.ai/c/thomson-reuters) (thomsonreuters.com)<br>It offers news and information tools for professionals in legal, regulatory, and tax sectors, helping them navigate complex environments. | Software Development | 🇨🇦 Toronto | 36,640 |  |
| 2 | [University of Toronto](https://www.tamtam.ai/c/university-of-toronto) (defygravitycampaign.utoronto.ca)<br>Leading Canadian university focused on research, innovation, and global education to address pressing societal challenges and prepare students for success | Higher Education | 🇨🇦 Toronto | 28,832 |  |
| 3 | [Celestica](https://www.tamtam.ai/c/celestica) (celestica.com)<br>Global leader in providing design, manufacturing, and supply chain solutions for aerospace, defense, communications, healthtech, and more, delivering innovative solutions for complex challenges | Technology, Information and Internet | 🇨🇦 Toronto | 16,022 | 1994 |
| 4 | [University Health Network](https://www.tamtam.ai/c/university-health-network) (uhn.ca)<br>Largest Canadian research hospital network specializing in patient care, medical research, education, and fundraising for advanced healthcare services. | Hospitals and Health Care | 🇨🇦 Toronto | 11,930 |  |
| 5 | [Ontario Power Generation](https://www.tamtam.ai/c/ontario-power-generation) (opg.com)<br>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 | Utilities | 🇨🇦 Toronto | 9,878 | 1999 |
| 6 | [Unity Health Toronto](https://www.tamtam.ai/c/unity-health-toronto) (unityhealth.to)<br>A health network in Toronto providing primary, community, specialized, and long-term care services, as well as investing in research and education | Hospitals and Health Care | 🇨🇦 Toronto | 8,686 | 2017 |
| 7 | [The Hospital for Sick Children](https://www.tamtam.ai/c/the-hospital-for-sick-children) (sickkids.ca)<br>Leading pediatric hospital integrating patient care, research, and education to advance children's health and develop innovative treatments globally. | Hospitals and Health Care | 🇨🇦 Toronto | 8,636 | 1875 |
| 8 | [Toronto Metropolitan University](https://www.tamtam.ai/c/toronto-metropolitan-university) (torontomu.ca)<br>Innovative urban university in Toronto, focusing on creativity, entrepreneurship, inclusivity, and global community engagement to serve societal needs | Higher Education | 🇨🇦 Toronto | 8,478 |  |
| 9 | [Sunnybrook](https://www.tamtam.ai/c/sunnybrook) (sunnybrook.ca)<br>A leading teaching hospital affiliated with the University of Toronto, specializing in patient care, groundbreaking research, and inventing the future of healthcare | Hospitals and Health Care | 🇨🇦 Toronto | 7,599 | 1948 |
| 10 | [Apotex Inc.](https://www.tamtam.ai/c/apotex-inc) (apotex.com)<br>A global pharmaceutical company producing affordable high-quality medicines, with divisions focusing on generics, biosimilars, consumer products, and API manufacturing | Pharmaceutical Manufacturing | 🇨🇦 Toronto | 6,548 |  |
| 11 | [St. Michael's Hospital](https://www.tamtam.ai/c/st-michael-s-hospital) (unityhealth.to)<br>A leading hospital providing compassionate care, medical education in 27 disciplines, and research through the Keenan Research Centre for global impact | Hospitals and Health Care | 🇨🇦 Toronto | 4,868 | 1892 |
| 12 | [CAMH](https://www.tamtam.ai/c/camh) (camh.ca)<br>A leading teaching hospital in Canada focused on transforming lives through clinical care, research, education, and advocacy for mental health and addiction issues | Hospitals and Health Care | 🇨🇦 Toronto | 4,477 | 1998 |
| 13 | [LifeLabs Medical Laboratory Services](https://www.tamtam.ai/c/lifelabs-medical-laboratory-services) (lifelabs.com)<br>A leading Canadian provider of diagnostic information and digital health systems, offering laboratory tests, genetics services, and online patient portals | Hospitals and Health Care | 🇨🇦 Toronto | 4,356 |  |
| 14 | [Sinai Health](https://www.tamtam.ai/c/sinai-health) (sinaihealth.ca)<br>A leading academic health science centre focused on integrated care, innovative research, and educating future healthcare leaders for comprehensive patient care | Hospitals and Health Care | 🇨🇦 Toronto | 4,083 |  |
| 15 | [ABC Technologies](https://www.tamtam.ai/c/abc-technologies) (abctechnologies.com)<br>A global leader in plastics and injection molding technology for the automotive industry, focusing on innovation, sustainability, and creating career opportunities | Motor Vehicle Manufacturing | 🇨🇦 Toronto | 4,059 | 1974 |
| 16 | [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 |
| 17 | [1Password](https://www.tamtam.ai/c/1password) (1password.com)<br>Protects business data, employee accounts, and sensitive information with secure access, sharing, and integration into existing systems. | Computer and Network Security | 🇨🇦 Toronto | 3,074 | 2005 |
| 18 | [Mount Sinai Hospital (Toronto), Sinai Health](https://www.tamtam.ai/c/mount-sinai-hospital-toronto-sinai-health) (mountsinai.on.ca)<br>Internationally recognized academic health sciences center providing exemplary patient care, nursing excellence, and top employer culture Flagship clinical programs available | Hospitals and Health Care | 🇨🇦 Toronto | 2,951 | 1923 |
| 19 | [Michael Garron Hospital](https://www.tamtam.ai/c/michael-garron-hospital) (tehn.ca)<br>A vibrant community hospital in East Toronto providing high-quality, patient-centred healthcare services along the continuum of care with strong partnerships | Hospitals and Health Care | 🇨🇦 Toronto | 2,219 | 1929 |
| 20 | [FGF Brands](https://www.tamtam.ai/c/fgf-brands) (fgfbrands.com)<br>Innovative technology-driven bakery pushing boundaries with sustainable ingredients, creating delicious baked goods and disrupting the global food industry for the better | Food and Beverage Manufacturing | 🇨🇦 Toronto | 2,195 | 2004 |
| 21 | [Give and Go Prepared Foods](https://www.tamtam.ai/c/give-and-go-prepared-foods) (giveandgo.com)<br>A leading manufacturer of sweet baked goods, offering indulgent treats under various brands, with a focus on innovation and quality for global retailers | Food and Beverage Manufacturing | 🇨🇦 Toronto | 2,143 | 1989 |
| 22 | [Colas Canada Inc.](https://www.tamtam.ai/c/colas-canada-inc) (colas.com)<br>A leading company in construction and maintenance of transportation infrastructure across Canada, part of a global group with operations worldwide | Construction | 🇨🇦 Toronto | 2,065 |  |
| 23 | [Baycrest](https://www.tamtam.ai/c/baycrest) (baycrest.org)<br>Global leader in aging and brain health innovations, offering comprehensive care for aging patients, conducting top research in cognitive neuroscience, and promoting global knowledge exchange | Hospitals and Health Care | 🇨🇦 Toronto | 1,407 | 1918 |
| 24 | [Kinectrics](https://www.tamtam.ai/c/kinectrics) (kinectrics.com)<br>Integrated lifecycle management services for electric power industry worldwide Testing, inspection, certification, engineering consulting, and maintenance services to ensure safe and efficient utility asset performance | Utilities | 🇨🇦 Toronto | 1,361 | 1912 |
| 25 | [OCAD University](https://www.tamtam.ai/c/ocad-university) (ocadu.ca)<br>A leading institution in Canada, specializing in art and design education for aspiring students to excel in their creative pursuits | Higher Education | 🇨🇦 Toronto | 1,343 | 1876 |
| 26 | [DECIEM \| THE ABNORMAL BEAUTY COMPANY](https://www.tamtam.ai/c/deciem-the-abnormal-beauty-company) (deciem.com)<br>A beauty brand umbrella offering high-quality, transparent skincare products, founded by a disrupter aiming to redefine beauty industry standards | Research Services | 🇨🇦 Toronto | 1,311 | 2013 |
| 27 | [Tenstorrent](https://www.tamtam.ai/c/tenstorrent) (tenstorrent.com)<br>Tenstorrent builds next-generation AI computers, combining expertise in computer architecture, ASIC design, systems, and neural network compilers Offices worldwide Join our team! | Computer Hardware Manufacturing | 🇨🇦 Toronto | 1,226 | 2016 |
| 28 | [Armstrong Fluid Technology](https://www.tamtam.ai/c/armstrong-fluid-technology) (armstrongfluidtechnology.com)<br>A global leader in intelligent fluid flow equipment and optimization technologies, focusing on HVAC, plumbing, gas transmission, and fire safety applications | Industrial Machinery Manufacturing | 🇨🇦 Toronto | 1,224 | 1934 |
| 29 | [Women's College Hospital](https://www.tamtam.ai/c/women-s-college-hospital) (womenscollegehospital.ca)<br>A pioneering healthcare institution focusing on women's health, innovation, and addressing Canada's healthcare challenges through interdisciplinary teams and equitable work environment | Hospitals and Health Care | 🇨🇦 Toronto | 1,200 |  |
| 30 | [Holland Bloorview Kids Rehabilitation Hospital](https://www.tamtam.ai/c/holland-bloorview-kids-rehabilitation-hospital) (hollandbloorview.ca)<br>Pioneering treatments, technologies, and programs for children with disabilities to fully participate in life through a world-class teaching hospital | Hospitals and Health Care | 🇨🇦 Toronto | 1,086 |  |

## 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 Toronto

- [The largest companies in Toronto](https://www.tamtam.ai/l/largest-companies-toronto) (1,921)
- [Multinational companies in Toronto](https://www.tamtam.ai/l/multinational-companies-toronto) (377)
- [Financial services firms in Toronto](https://www.tamtam.ai/l/financial-services-firms-toronto) (250)
- [Financial Services companies in Toronto](https://www.tamtam.ai/l/financial-services-companies-toronto) (163)
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- [Software Development companies in Toronto](https://www.tamtam.ai/l/software-development-companies-toronto) (131)
- [Critical infrastructure operators in Toronto](https://www.tamtam.ai/l/critical-infrastructure-operators-toronto) (120)
- [Professional services firms in Toronto](https://www.tamtam.ai/l/professional-services-firms-toronto) (117)
- [Retail chains in Toronto](https://www.tamtam.ai/l/retail-chains-toronto) (116)
- [Education providers in Toronto](https://www.tamtam.ai/l/education-companies-toronto) (109)
- [IT Services and IT Consulting companies in Toronto](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-toronto) (100)
- [Companies with a mobile app in Toronto](https://www.tamtam.ai/l/companies-with-mobile-app-toronto) (97)
- [Subscription businesses in Toronto](https://www.tamtam.ai/l/subscription-businesses-toronto) (93)
- [Investment Management companies in Toronto](https://www.tamtam.ai/l/investment-management-companies-toronto) (92)
- [Manufacturers in Toronto](https://www.tamtam.ai/l/manufacturers-toronto) (88)
- [Publicly traded companies in Toronto](https://www.tamtam.ai/l/publicly-traded-companies-toronto) (86)
- [AI companies in Toronto](https://www.tamtam.ai/l/ai-companies-toronto) (82)
- [Consulting firms in Toronto](https://www.tamtam.ai/l/consulting-firms-toronto) (70)
- [Healthcare providers in Toronto](https://www.tamtam.ai/l/healthcare-providers-toronto) (68)
- [Advertising Services companies in Toronto](https://www.tamtam.ai/l/advertising-services-companies-toronto) (66)
- [Hospitals and Health Care companies in Toronto](https://www.tamtam.ai/l/hospitals-and-health-care-companies-toronto) (66)
- [IT services companies in Toronto](https://www.tamtam.ai/l/it-services-companies-toronto) (66)
- [Public sector organisations in Toronto](https://www.tamtam.ai/l/public-sector-organisations-toronto) (64)
- [Retail companies in Toronto](https://www.tamtam.ai/l/retail-companies-toronto) (61)

## The same list elsewhere in Canada

- [Companies with in-house R&D in Canada](https://www.tamtam.ai/l/r-and-d-companies-canada) (678)
- [Companies with in-house R&D in Ontario](https://www.tamtam.ai/l/r-and-d-companies-ontario) (300)
- [Companies with in-house R&D in the province of Quebec](https://www.tamtam.ai/l/r-and-d-companies-province-of-quebec) (159)
- [Companies with in-house R&D in British Columbia](https://www.tamtam.ai/l/r-and-d-companies-british-columbia) (76)
- [Companies with in-house R&D in Alberta](https://www.tamtam.ai/l/r-and-d-companies-alberta) (74)
- [Companies with in-house R&D in Montreal](https://www.tamtam.ai/l/r-and-d-companies-montreal) (59)
- [Companies with in-house R&D in Calgary](https://www.tamtam.ai/l/r-and-d-companies-calgary) (39)
- [Companies with in-house R&D in Vancouver](https://www.tamtam.ai/l/r-and-d-companies-vancouver) (34)

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Source: https://www.tamtam.ai/l/r-and-d-companies-toronto