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.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
GFL Environmental Inc.gflenv.com
A leading North American provider of environmental services for solid waste, liquid waste, and soil remediation, focusing on customer service, safety, and compliance |
8,244 | |||
| 2 |
Region of Peelpeelregion.ca
A diverse and inclusive organization in Peel Region delivering social services and infrastructure for residents and businesses, fostering a Community for Life |
4,959 | |||
| 3 |
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 | |||
| 4 |
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 | |||
| 5 |
York Region (The Regional Municipality of York)york.ca
The company provides services to 12 million residents, 54,000 businesses, and 650,000 employees in a two-tier government structure |
3,799 | |||
| 6 |
Libertyjobs.libertyenergyandwater.com
Provider of essential energy and water services, including clean, renewable power generation, with a focus on sustainability and customer satisfaction |
3,364 | |||
| 7 |
Durham Region (The Regional Municipality of Durham)durham.ca
Durham Region provides a wide range of services to a group of diverse communities, including paramedics, recycling, water supply, transit, and social programs |
2,624 | |||
| 8 |
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 | |||
| 9 | 2,185 | ||||
| 10 |
Region of Waterlooregionofwaterloo.ca
Provides municipal services including transit, waste management, health, housing, and employs over 3,500 people in diverse roles. |
2,165 | |||
| 11 |
Niagara Regionniagararegion.ca
Providing essential municipal services including water, roads, waste collection, public safety, and housing to support a diverse community. |
2,038 | |||
| 12 |
Halton Regionhalton.ca
Providing high-quality programs and services supporting safe, healthy communities and economic growth across multiple municipalities in Halton Region. |
1,992 | |||
| 13 |
City of London, Canadalondon.ca
A large team of over 3000 employees in London delivering 100+ services, working together to build a better city for all |
1,749 | |||
| 14 |
Environment, Conservation and Parks | Environnement, Protection de la nature et Parcsontario.ca
Environmental organization responsible for conservation, protection, and management of Ontario's environment, nature, and parks in Canada |
1,711 | |||
| 15 |
City of Windsorcitywindsor.ca
Provides municipal services and governance for Windsor, Ontario, including public inquiries and community support through accessible contact numbers. |
1,515 | |||
| 16 |
City of Greater Sudburygreatersudbury.ca
Dynamic team in Northeastern Ontario's regional capital focused on enhancing citizens' quality of life through services in technology, tourism, education, government, and health |
1,443 | |||
| 17 |
Waste Connections of Canadawasteconnectionscanada.com
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 |
1,428 | |||
| 18 |
Defence Construction Canadadcc-cdc.gc.ca
A Crown corporation providing contracting, construction management, infrastructure, environmental, and lifecycle support services for Canada's defence requirements through five service lines |
1,372 | |||
| 19 |
City Of Guelphguelph.ca
Provides diverse public programs and services supporting community well-being, inclusion, employee development, and environmental care in a growing city. |
1,318 | |||
| 20 |
Chemtradechemtradelogistics.com
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 |
1,242 | |||
| 21 |
City of Barriebarrie.ca
Provides municipal services, maintains infrastructure, supports community development, and fosters connections to improve quality of life for residents. |
1,185 | |||
| 22 |
City of Kingstoncityofkingston.ca
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 |
1,103 | |||
| 23 |
Votorantim Cimentos North America (VCNA)votorantimcimentos.com
Leading provider of cement, concrete and aggregates in North America, part of a global building materials and sustainability solutions provider |
1,044 | |||
| 24 |
Toronto and Region Conservation Authority (TRCA)trca.ca
A conservation authority in Ontario safeguarding and enhancing watershed communities by protecting, restoring natural environments, and promoting sustainable practices for growing regions |
967 | |||
| 25 |
City of Thunder Baythunderbay.ca
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 |
877 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 26 |
Pinchin in Canadapinchin.com
An environmental consulting firm offering services in engineering, building science, health & safety, asbestos abatement, emissions reduction, and environmental compliance across North America |
871 | |||
| 27 |
City of Brantfordbrantford.ca
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 |
854 | |||
| 28 |
Giampaolo Group Inc.
Fully integrated metal management company with operations in metal recycling, steel processing, aluminum production, real estate development, and charitable fundraising events for various causes |
829 | |||
| 29 |
Trojan Technologiestrojantechnologies.com
The company provides innovative technologies to help customers meet water quality objectives, reduce costs, and improve environmental stewardship globally |
796 | |||
| 30 |
Municipality of Chatham-Kentchatham-kent.ca
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 |
773 | |||
| 31 |
City of Waterloowaterloo.ca
Provides diverse municipal jobs and services, supports employee development, promotes safety, diversity, and community involvement for residents. |
754 | |||
| 32 |
Ontario Clean Water Agencyocwa.com
Provider of water and wastewater management services, offering safe, reliable, and cost-effective solutions to municipalities, businesses, and institutions in Ontario |
745 | |||
| 33 |
Miller Waste Systems Inc.millerwaste.ca
A Canadian waste management leader offering collection, recycling, composting, and hazardous waste solutions while also producing renewable energy and fertilizer |
683 | |||
| 34 |
City of Peterboroughpeterborough.ca
A diverse and inclusive community in Central Ontario, offering a variety of career opportunities with competitive compensation and excellent benefits |
658 | |||
| 35 |
Greenfield Globalgreenfield.com
Global supplier of high-purity alcohols, specialty solvents, and renewable fuels, facilitating sustainability through innovative solutions for various industries worldwide |
655 | |||
| 36 |
Emterra Groupemterra.ca
Family-owned leader in recycling and waste management for industrial, commercial, residential, and municipal customers in Canada and USA, diverting waste from landfills. |
651 | |||
| 37 |
City of St. Catharinesstcatharines.ca
A vibrant city in the Niagara Region offering diverse attractions, festivals, and experiences to enhance quality of life for residents and visitors alike |
638 | |||
| 38 |
City of Sault Ste. Mariesaultstemarie.ca
Leading municipal corporation promoting economic and social growth through efficient provision of services and community partnerships |
571 | |||
| 39 |
City of Cambridge Ontariocambridge.ca
Fast-growing city with diverse industries including manufacturing, technology, pharmaceuticals, and services, fostering a multicultural, close-knit community with strong values. |
556 | |||
| 40 |
Tomlinson Group of Companiestomlinsongroup.com
Multidisciplinary construction and environmental services provider with expertise in infrastructure projects, site development, material management, and innovative solutions |
539 | |||
| 41 |
City of Niagara Fallsniagarafalls.ca
The company promotes Niagara Falls as a family-friendly location with various activities, beautiful trails, golf courses, and community-focused recreational amenities |
536 | |||
| 42 |
Maxxam Analyticsbvna.com
A leading provider of analytical services for energy, environmental, food, industrial hygiene, and DNA industries, supporting decision-making with rigorous science and expertise |
480 | |||
| 43 |
Conestoga-Rovers & Associates (CRA), A GHD Companyghd.com
A global leader in engineering, environmental consulting, and construction services created through a merger in July 2014 Visit website for more information |
473 | |||
| 44 |
Abell Pest Controlabellpestcontrol.com
A family-owned pest management company providing professional, effective, and courteous services for over 90 years across North America |
450 | |||
| 45 |
Environmental 360 Solutionse360s.ca
A leading environmental management provider offering end-to-end solutions for municipalities, commercial, and industrial clients while prioritizing health, safety, and environmental protection |
446 | |||
| 46 |
Walker Industrieswalkerind.com
A family-owned company offering high-performance products and services in industries such as renewable energy, waste disposal, aggregates, and road construction |
422 | |||
| 47 |
Oxford Countyoxfordcounty.ca
A municipal government in southwestern Ontario focused on sustainable growth, renewable energy, waste reduction, poverty alleviation, and providing various community services |
416 | |||
| 48 |
R.J. Burnside & Associates Limitedrjburnside.com
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 |
407 | |||
| 49 |
Orkin Canadaorkincanada.ca
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 |
403 | |||
| 50 |
County of Brantbrant.ca
The County of Brant seeks motivated individuals to create a vibrant, safe, and caring community, offering services to residents, visitors, and businesses |
371 | |||
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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 Nov 12, 2026.
More company lists in Ontario
- The largest companies in Ontario 5,032
- Multinational companies in Ontario 901
- Financial services firms in Ontario 396
- Manufacturers in Ontario 389
- Critical infrastructure operators in Ontario 344
- Retail chains in Ontario 327
- Companies with in-house R&D in Ontario 300
- Logistics companies in Ontario 285
- Education providers in Ontario 276
- SaaS companies in Ontario 275
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- Publicly traded companies in Ontario 156
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The same list elsewhere in Canada
- Environmental services companies in the province of Quebec 36
- Environmental services companies in Alberta 33
- Environmental services companies in British Columbia 26