# Environmental services companies headquartered in Ontario

Tamtam tracks 71 environmental services companies headquartered in Ontario. This list ranks the 50 largest by number of employees on LinkedIn, led by GFL Environmental Inc., Region of Peel and City Of Hamilton. Their median headcount is 877. Half of them were founded in 1972 or later. The most common headquarters are Toronto (5), Mississauga (4) and Oakville (4).

This selection of large companies in Ontario operating in environmental services includes several government administration bodies, reflecting the public sector's role in this field. Among them are the Region of Peel, providing social services and infrastructure, and the City of Brampton, focused on technology and environmental innovation. Other key players include GFL Environmental Inc., a North American provider of solid waste and soil remediation services, and Liberty, which delivers essential energy and water services.

The data shows a strong concentration of government administration entities, with many regional and city municipalities such as the City of Hamilton and York Region. These organizations often handle services like waste management, water supply, and environmental protection. Canadian Nuclear Laboratories, based in Chalk River, specializes in nuclear science and technology, including waste management.

🇨🇦 Ontario · 50 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [GFL Environmental Inc.](https://www.tamtam.ai/c/gfl-environmental-inc) (gflenv.com)<br>A leading North American provider of environmental services for solid waste, liquid waste, and soil remediation, focusing on customer service, safety, and compliance | Environmental Services | 🇨🇦 Vaughan | 8,244 |  |
| 2 | [Region of Peel](https://www.tamtam.ai/c/region-of-peel) (peelregion.ca)<br>A diverse and inclusive organization in Peel Region delivering social services and infrastructure for residents and businesses, fostering a Community for Life | Government Administration | 🇨🇦 Brampton | 4,959 | 1974 |
| 3 | [City Of Hamilton](https://www.tamtam.ai/c/city-of-hamilton) (hamilton.ca)<br>The organization aims to provide high-quality public services for a healthy, safe, and prosperous community while fostering collective ownership and diversity | Government Administration | 🇨🇦 Hamilton | 4,633 |  |
| 4 | [City of Brampton](https://www.tamtam.ai/c/city-of-brampton) (brampton.ca)<br>City with diverse cultures and innovative spirit focusing on technology, environmental innovation, and community-driven progress for residents and businesses. | Government Administration | 🇨🇦 Brampton | 4,240 |  |
| 5 | [York Region (The Regional Municipality of York)](https://www.tamtam.ai/c/york-region-the-regional-municipality-of-york) (york.ca)<br>The company provides services to 12 million residents, 54,000 businesses, and 650,000 employees in a two-tier government structure | Government Administration | 🇨🇦 Newmarket | 3,799 |  |
| 6 | [Liberty](https://www.tamtam.ai/c/liberty) (jobs.libertyenergyandwater.com)<br>Provider of essential energy and water services, including clean, renewable power generation, with a focus on sustainability and customer satisfaction | Utilities | 🇨🇦 Oakville | 3,364 | 1988 |
| 7 | [Durham Region (The Regional Municipality of Durham)](https://www.tamtam.ai/c/durham-region-the-regional-municipality-of-durham) (durham.ca)<br>Durham Region provides a wide range of services to a group of diverse communities, including paramedics, recycling, water supply, transit, and social programs | Government Administration | 🇨🇦 Whitby | 2,624 | 1974 |
| 8 | [Canadian Nuclear Laboratories](https://www.tamtam.ai/c/canadian-nuclear-laboratories) (cnl.ca)<br>A leading organization in nuclear science and technology, specializing in research, development, engineering, waste management, and decommissioning services for various applications | Research Services | 🇨🇦 Chalk River | 2,340 | 2014 |
| 9 | [Shred-it](https://www.tamtam.ai/c/shred-it) (linktr.ee)<br>Secure shredding and recycling of confidential papers and hard drives, protecting businesses from data fraud across North America and Europe. | Information Services | 🇨🇦 Oakville | 2,185 | 1988 |
| 10 | [Region of Waterloo](https://www.tamtam.ai/c/region-of-waterloo) (regionofwaterloo.ca)<br>Provides municipal services including transit, waste management, health, housing, and employs over 3,500 people in diverse roles. | Government Administration | 🇨🇦 Kitchener | 2,165 | 1973 |
| 11 | [Niagara Region](https://www.tamtam.ai/c/niagara-region) (niagararegion.ca)<br>Providing essential municipal services including water, roads, waste collection, public safety, and housing to support a diverse community. | Government Administration | 🇨🇦 Thorold | 2,038 | 1970 |
| 12 | [Halton Region](https://www.tamtam.ai/c/halton-region) (halton.ca)<br>Providing high-quality programs and services supporting safe, healthy communities and economic growth across multiple municipalities in Halton Region. | Government Administration | 🇨🇦 Oakville | 1,992 | 1974 |
| 13 | [City of London, Canada](https://www.tamtam.ai/c/city-of-london-canada) (london.ca)<br>A large team of over 3000 employees in London delivering 100+ services, working together to build a better city for all | Government Administration | 🇨🇦 London | 1,749 |  |
| 14 | [Environment, Conservation and Parks \| Environnement, Protection de la nature et Parcs](https://www.tamtam.ai/c/environment-conservation-and-parks-environnement-protection-de-la-nature-et) (ontario.ca)<br>Environmental organization responsible for conservation, protection, and management of Ontario's environment, nature, and parks in Canada | Government Administration | 🇨🇦 Toronto | 1,711 | 1972 |
| 15 | [City of Windsor](https://www.tamtam.ai/c/city-of-windsor) (citywindsor.ca)<br>Provides municipal services and governance for Windsor, Ontario, including public inquiries and community support through accessible contact numbers. | Government Administration | 🇨🇦 Windsor | 1,515 | 1892 |
| 16 | [City of Greater Sudbury](https://www.tamtam.ai/c/city-of-greater-sudbury) (greatersudbury.ca)<br>Dynamic team in Northeastern Ontario's regional capital focused on enhancing citizens' quality of life through services in technology, tourism, education, government, and health | Government Administration | 🇨🇦 Sudbury | 1,443 |  |
| 17 | [Waste Connections of Canada](https://www.tamtam.ai/c/waste-connections-of-canada) (wasteconnectionscanada.com)<br>Canada's leading waste management company providing collection, recycling, and disposal services for commercial, industrial, municipal, and residential customers, promoting environmental sustainability and smart waste solutions | Environmental Services | 🇨🇦 Vaughan | 1,428 |  |
| 18 | [Defence Construction Canada](https://www.tamtam.ai/c/defence-construction-canada) (dcc-cdc.gc.ca)<br>A Crown corporation providing contracting, construction management, infrastructure, environmental, and lifecycle support services for Canada's defence requirements through five service lines | Construction | 🇨🇦 Ottawa | 1,372 | 1951 |
| 19 | [City Of Guelph](https://www.tamtam.ai/c/city-of-guelph) (guelph.ca)<br>Provides diverse public programs and services supporting community well-being, inclusion, employee development, and environmental care in a growing city. | Government Administration | 🇨🇦 Guelph | 1,318 | 1827 |
| 20 | [Chemtrade](https://www.tamtam.ai/c/chemtrade) (chemtradelogistics.com)<br>A publicly traded chemical manufacturing and handling company based in Toronto, operating in North America and Brazil, providing industrial chemicals and services to various industries | Chemical Manufacturing | 🇨🇦 Toronto | 1,242 | 2001 |
| 21 | [City of Barrie](https://www.tamtam.ai/c/city-of-barrie) (barrie.ca)<br>Provides municipal services, maintains infrastructure, supports community development, and fosters connections to improve quality of life for residents. | Government Administration | 🇨🇦 Barrie | 1,185 |  |
| 22 | [City of Kingston](https://www.tamtam.ai/c/city-of-kingston) (cityofkingston.ca)<br>The company is dedicated to creating a smart, livable 21st century city with a diverse economy, world-class institutions, and vibrant entertainment and tourism activities | Government Administration | 🇨🇦 Kingston | 1,103 |  |
| 23 | [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 |
| 24 | [Toronto and Region Conservation Authority (TRCA)](https://www.tamtam.ai/c/toronto-and-region-conservation-authority-trca) (trca.ca)<br>A conservation authority in Ontario safeguarding and enhancing watershed communities by protecting, restoring natural environments, and promoting sustainable practices for growing regions | Environmental Services | 🇨🇦 Toronto | 967 | 1957 |
| 25 | [City of Thunder Bay](https://www.tamtam.ai/c/city-of-thunder-bay) (thunderbay.ca)<br>This organization in Thunder Bay focuses on promoting economic development, education, and a clean, green community while supporting a high quality of life for residents | Government Administration | 🇨🇦 Thunder Bay | 877 |  |
| 26 | [Pinchin in Canada](https://www.tamtam.ai/c/pinchin-in-canada) (pinchin.com)<br>An environmental consulting firm offering services in engineering, building science, health & safety, asbestos abatement, emissions reduction, and environmental compliance across North America | Environmental Services | 🇨🇦 Mississauga | 871 |  |
| 27 | [City of Brantford](https://www.tamtam.ai/c/city-of-brantford) (brantford.ca)<br>Dedicated community staff deliver programs/services to enhance residents' quality of life CAO leads departments to meet community demands/expectations Talent investment for building a better city | Government Administration | 🇨🇦 Brantford | 854 |  |
| 28 | [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 |
| 29 | [Trojan Technologies](https://www.tamtam.ai/c/trojan-technologies) (trojantechnologies.com)<br>The company provides innovative technologies to help customers meet water quality objectives, reduce costs, and improve environmental stewardship globally | Environmental Services | 🇨🇦 London | 796 | 1947 |
| 30 | [Municipality of Chatham-Kent](https://www.tamtam.ai/c/municipality-of-chatham-kent) (chatham-kent.ca)<br>A municipality in Ontario with a population of 100,000+, Chatham-Kent focuses on providing services, preserving heritage, and promoting economic growth in a diverse region | Government Administration | 🇨🇦 Chatham | 773 | 1998 |
| 31 | [City of Waterloo](https://www.tamtam.ai/c/city-of-waterloo) (waterloo.ca)<br>Provides diverse municipal jobs and services, supports employee development, promotes safety, diversity, and community involvement for residents. | Government Administration | 🇨🇦 Waterloo | 754 |  |
| 32 | [Ontario Clean Water Agency](https://www.tamtam.ai/c/ontario-clean-water-agency) (ocwa.com)<br>Provider of water and wastewater management services, offering safe, reliable, and cost-effective solutions to municipalities, businesses, and institutions in Ontario | Environmental Services | 🇨🇦 Mississauga | 745 | 1993 |
| 33 | [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 |
| 34 | [City of Peterborough](https://www.tamtam.ai/c/city-of-peterborough) (peterborough.ca)<br>A diverse and inclusive community in Central Ontario, offering a variety of career opportunities with competitive compensation and excellent benefits | Government Administration | 🇨🇦 Peterborough | 658 |  |
| 35 | [Greenfield Global](https://www.tamtam.ai/c/greenfield-global) (greenfield.com)<br>Global supplier of high-purity alcohols, specialty solvents, and renewable fuels, facilitating sustainability through innovative solutions for various industries worldwide | Manufacturing | 🇨🇦 Toronto | 655 | 1989 |
| 36 | [Emterra Group](https://www.tamtam.ai/c/emterra-group) (emterra.ca)<br>Family-owned leader in recycling and waste management for industrial, commercial, residential, and municipal customers in Canada and USA, diverting waste from landfills. | Environmental Services | 🇨🇦 Oakville | 651 | 1976 |
| 37 | [City of St. Catharines](https://www.tamtam.ai/c/city-of-st-catharines) (stcatharines.ca)<br>A vibrant city in the Niagara Region offering diverse attractions, festivals, and experiences to enhance quality of life for residents and visitors alike | Government Administration | 🇨🇦 St. Catharines | 638 | 1876 |
| 38 | [City of Sault Ste. Marie](https://www.tamtam.ai/c/city-of-sault-ste-marie) (saultstemarie.ca)<br>Leading municipal corporation promoting economic and social growth through efficient provision of services and community partnerships | Government Administration | 🇨🇦 Sault Ste. Marie | 571 | 1912 |
| 39 | [City of Cambridge Ontario](https://www.tamtam.ai/c/city-of-cambridge-ontario) (cambridge.ca)<br>Fast-growing city with diverse industries including manufacturing, technology, pharmaceuticals, and services, fostering a multicultural, close-knit community with strong values. | Government Administration | 🇨🇦 Cambridge | 556 |  |
| 40 | [Tomlinson Group of Companies](https://www.tamtam.ai/c/tomlinson-group-of-companies) (tomlinsongroup.com)<br>Multidisciplinary construction and environmental services provider with expertise in infrastructure projects, site development, material management, and innovative solutions | Construction | 🇨🇦 Ottawa | 539 | 1952 |
| 41 | [City of Niagara Falls](https://www.tamtam.ai/c/city-of-niagara-falls) (niagarafalls.ca)<br>The company promotes Niagara Falls as a family-friendly location with various activities, beautiful trails, golf courses, and community-focused recreational amenities | Government Administration | 🇨🇦 Niagara Falls | 536 | 1904 |
| 42 | [Maxxam Analytics](https://www.tamtam.ai/c/maxxam-analytics) (bvna.com)<br>A leading provider of analytical services for energy, environmental, food, industrial hygiene, and DNA industries, supporting decision-making with rigorous science and expertise | Environmental Services | 🇨🇦 Mississauga | 480 |  |
| 43 | [Conestoga-Rovers & Associates (CRA), A GHD Company](https://www.tamtam.ai/c/conestoga-rovers-and-associates-cra-a-ghd-company) (ghd.com)<br>A global leader in engineering, environmental consulting, and construction services created through a merger in July 2014 Visit website for more information | Civil Engineering | 🇨🇦 Waterloo | 473 |  |
| 44 | [Abell Pest Control](https://www.tamtam.ai/c/abell-pest-control) (abellpestcontrol.com)<br>A family-owned pest management company providing professional, effective, and courteous services for over 90 years across North America | Environmental Services | 🇨🇦 Etobicoke | 450 | 1924 |
| 45 | [Environmental 360 Solutions](https://www.tamtam.ai/c/environmental-360-solutions) (e360s.ca)<br>A leading environmental management provider offering end-to-end solutions for municipalities, commercial, and industrial clients while prioritizing health, safety, and environmental protection | Environmental Services | 🇨🇦 Aurora | 446 | 2018 |
| 46 | [Walker Industries](https://www.tamtam.ai/c/walker-industries) (walkerind.com)<br>A family-owned company offering high-performance products and services in industries such as renewable energy, waste disposal, aggregates, and road construction | Wholesale Building Materials | 🇨🇦 Thorold | 422 | 1887 |
| 47 | [Oxford County](https://www.tamtam.ai/c/oxford-county) (oxfordcounty.ca)<br>A municipal government in southwestern Ontario focused on sustainable growth, renewable energy, waste reduction, poverty alleviation, and providing various community services | Government Administration | 🇨🇦 Woodstock | 416 |  |
| 48 | [R.J. Burnside & Associates Limited](https://www.tamtam.ai/c/r-j-burnside-and-associates-limited) (rjburnside.com)<br>Employee-owned engineering and environmental consultancy firm with expertise in various disciplines, serving clients in Canada and internationally with responsive services and a positive working environment | Civil Engineering | 🇨🇦 Orangeville | 407 | 1970 |
| 49 | [Orkin Canada](https://www.tamtam.ai/c/orkin-canada) (orkincanada.ca)<br>Leading pest control provider in Canada with over a century of expertise, offering customized solutions for residential, commercial, industrial, and government clients backed by comprehensive guarantees | Environmental Services | 🇨🇦 Mississauga | 403 | 1901 |
| 50 | [County of Brant](https://www.tamtam.ai/c/county-of-brant) (brant.ca)<br>The County of Brant seeks motivated individuals to create a vibrant, safe, and caring community, offering services to residents, visitors, and businesses | Government Administration | 🇨🇦 Burford | 371 |  |

## 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 12, 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

- [Environmental services companies in the province of Quebec](https://www.tamtam.ai/l/environmental-services-companies-province-of-quebec) (36)
- [Environmental services companies in Alberta](https://www.tamtam.ai/l/environmental-services-companies-alberta) (33)
- [Environmental services companies in British Columbia](https://www.tamtam.ai/l/environmental-services-companies-british-columbia) (26)

## The same list elsewhere

- [Environmental services companies in the world](https://www.tamtam.ai/l/environmental-services-companies-in-the-world) (4,213)
- [Environmental services companies in North America](https://www.tamtam.ai/l/environmental-services-companies-in-north-america) (1,043)

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Source: https://www.tamtam.ai/l/environmental-services-companies-ontario-canada