Company lists · Data refreshed September 2026
Top 25 Esg consulting firms based in the United States
RevenueBase identified 2,874 esg consulting firms headquartered in the United States as of September 2026 and tracks 47,277 professional contacts across them, including 20,646 with verified work emails and 18,134 with mobile numbers. New York is the largest hub.
This list covers esg consulting firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 2, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest esg consulting firms based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 2,644 contacts → | ||||
Indirect evidence “APTIM enhances the quality of the environment, wellbeing of people, resilience of communities, and opportunity for employees to make a difference, not just a living.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 2 | 2,198 contacts → | ||||
Partial evidence “Baringa is a global consulting firm that helps leaders drive meaningful change and create value.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,618 contacts → | ||||
Partial evidence “Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 4 | 1,516 contacts → | ||||
Indirect evidence “Onterris (formerly Montrose Environmental Group) was one of the first to see environmental responsibility as not just an imperative but as a strategic asset.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 5 | 1,345 contacts → | ||||
Indirect evidence “Sphera creates a safer, more sustainable and productive world.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 6 | 1,146 contacts → | ||||
Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 7 | 949 contacts → | ||||
Indirect evidence “Trinity Consultants is a global team of experts helping organizations solve complex challenges in environmental compliance, ecological protection, infrastructure performance, and…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 8 | 682 contacts → | ||||
Indirect evidence “INERCO, with 30 years of experience, offers comprehensive services and develops advanced technologies that contribute to sustainable industrial development, acting as a leader in…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 9 | 658 contacts → | ||||
Partial evidence “Antea Group is an international engineering and environmental consulting firm specializing in full-service solutions in the fields of environment, health and safety, and…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 10 | 566 contacts → | ||||
Indirect evidence “For more than 25 years, SolomonEdwards has empowered organizations to tackle common and complex business challenges through strategic advisory, technical advocacy, and hands-on…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 11 | 537 contacts → | ||||
Indirect evidence “Watershed is the enterprise sustainability platform.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 12 | 530 contacts → | ||||
Indirect evidence “For 35 years we have been helping investors, lenders, owners, developers, contractors, and property managers reduce risk and optimize their built facilities, infrastructure and…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 13 | 483 contacts → | ||||
Partial evidence “Rincon Consultants is a multi-disciplinary environmental sciences, planning, and engineering consulting firm that provides quality professional services to government and industry.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 14 | 463 contacts → | ||||
Indirect evidence “At Enhesa we empower the world’s largest businesses to achieve compliance, manage risk, and drive sustainability with clear, actionable insights.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 15 | 452 contacts → | ||||
Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 16 | 435 contacts → | ||||
Partial evidence “Founded 40 years ago, Roux is recognized for being a highly effective, client-focused environmental consulting and management firm.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 17 | 420 contacts → | ||||
Indirect evidence “Sedex is a global technology company that specialises in data, insights and professional services to empower supply chain sustainability.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 18 | 382 contacts → | ||||
Indirect evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 19 | 370 contacts → | ||||
Indirect evidence “P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 20 | 330 contacts → | ||||
Partial evidence “ALL4 is a global consulting firm committed to shaping a sustainable future through innovative environmental, health, and safety (EHS) and digital solutions.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 21 | 303 contacts → | ||||
Partial evidence “Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 22 | 288 contacts → | ||||
Indirect evidence “With over a century’s worth of experience, nearly 4,300 global team members, and 30 locations including global subsidiaries, our firm serves clients in 30 different industries…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 23 | 277 contacts → | ||||
Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 24 | 221 contacts → | ||||
Indirect evidence “At Kleinschmidt, we work primarily with energy companies and government agencies in North America to protect and enhance the environment without compromising performance.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 25 | 211 contacts → | ||||
Indirect evidence “PEG presents a comprehensive capacity for the evaluation and understanding of a broad base of energy and environmental sustainability related programs, policies and initiatives.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: esg consulting firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names esg consulting firms.
- Partial evidence
- Its own public description names part of esg consulting firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name esg consulting firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 2,874 esg consulting firms based in the United States
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Esg consulting firms based in the United States at a glance
As of Sep 2, 2026Companies by employee count
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among esg consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “esg consulting firms”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names esg consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among esg consulting firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 20,646 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 2, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names esg consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many esg consulting firms are there based in the United States?
RevenueBase identified 2,874 esg consulting firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
APTIM, headquartered in Wichita, tops this list with the largest team on record.
Which city has the most esg consulting firms?
New York leads with 153 headquartered companies, followed by Washington (80) and Houston (75).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 20,646 verified decision-maker contacts tracked across these 2,874 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 2, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.