Company lists · Data refreshed September 2026
Top 25 Constituent relations firms worldwide
RevenueBase identified 1,135 constituent relations firms worldwide as of September 2026 and tracks 9,307 professional contacts across them, including 3,751 with verified work emails. The United States is the largest market and Washington the largest hub.
This list covers constituent relations firms worldwide, 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 19, 2026. Country and city lists for constituent relations firms follow the table.
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 constituent relations firms worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 390 contacts → | ||||
Partial evidence “Mercury is a national bipartisan government relations and strategic communications firm.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 362 contacts → | ||||
Indirect evidence “Somos una empresa consultora en asuntos públicos que conjunta sustancia con forma y traduce pensamiento al considerar gran diversidad de puntos de vista y panoramas.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 349 contacts → | ||||
Partial evidence “DKC is a full service public relations, marketing and government affairs firm and part of the Acceleration Community of Companies, Based in New York City, and with offices in Los…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 302 contacts → | ||||
Indirect evidence “Our primary interest at FLS Connect is to understand your campaign’s mission and objective and work closely to design efforts that meet your needs.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 255 contacts → | ||||
Partial evidence “Cornerstone Government Affairs is a full-service, bipartisan, employee-owned firm specializing in government relations and lobbying, public affairs, strategic communications, and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 220 contacts → | ||||
Partial evidence “SKDK provides strategic advice, public relations, crisis communications, advertising, direct mail, and research to national and international companies, advocacy organizations…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 179 contacts → | ||||
Indirect evidence “Global Strategy Group is the go-to public affairs, communications, and research partner for companies, causes, and campaigns.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 166 contacts → | ||||
Indirect evidence “Invariant is a bipartisan business advisory firm, providing strategic advice to companies, trade associations, non-profits, and individuals on how to make Washington work for them.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 97 contacts → | ||||
Partial evidence “Monument Advocacy is a bipartisan firm that offers government relations, public affairs, strategic and crisis communications, and digital services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 96 contacts → | ||||
Partial evidence “Justice Works Youth Care is a Government Relations company located in 615 Virginia Ave, Rochester, Pennsylvania, United States.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 84 contacts → | ||||
Indirect evidence “Founded in 1989 and independently owned by our principals, Earnscliffe operates from offices in Ottawa-Gatineau, Toronto and Vancouver.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 84 contacts → | ||||
Indirect evidence “Founded in 1982, The Ferguson Group has a proud record of success advocating on behalf of local communities.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 77 contacts → | ||||
Partial evidence “Established in 1998, Sussex Strategy Group is Canada’s leading government relations, strategic communications, digital advocacy and business advisory agency.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 72 contacts → | ||||
Partial evidence “Larson Shannahan Slifka Group (LS2group) is a bipartisan public relations, public affairs, and marketing firm that guides its practices with one goal in mind: what others may do…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 66 contacts → | ||||
Indirect evidence “Bose Public Affairs Group successfully advocates for our clients’ legislative, regulatory, procurement, political and communication interests with offices in Indianapolis and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 63 contacts → | ||||
Partial evidence “Capitol Counsel, LLC is a full service government relations firm providing political analysis, strategic advice and advocacy services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 62 contacts → | ||||
Partial evidence “GR Japan is the leading government relations and public affairs firm in Tokyo.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 57 contacts → | ||||
Indirect evidence “We are innovators and thought leaders who believe in developing robust integrated solutions for our clients.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 55 contacts → | ||||
Indirect evidence “At Beekeeper Group we believe in empowering people to advocate for impact by connecting them with stakeholders that are ready to take action so that our clients can achieve their…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 53 contacts → | ||||
Indirect evidence “Smart strategy begins with being well informed.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 53 contacts → | ||||
Partial evidence “TRG is a government relations consulting firm located on the doorstep of the United States Capitol.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 53 contacts → | ||||
Indirect evidence “Founded in January 2001 by Gabriel Guerra Castellanos, GC & A is a specialized consulting firm that offers strategic communication, lobbying, as well as government and community…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 50 contacts → | ||||
Indirect evidence “Somos consultores estratégicos de asuntos públicos.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 43 contacts → | ||||
Partial evidence “The Livingston Group (TLG) has delivered comprehensive government relations and lobbying services in Washington DC and globally since With nine different practice areas, our…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 40 contacts → | ||||
Partial evidence “S-3 is a full service policy and government relations firm providing comprehensive solutions in government affairs and public relations to top tier clients whose priorities demand…” Source: RevenueBase Database · checked Sep 19, 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: constituent relations 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 constituent relations firms.
- Partial evidence
- Its own public description names part of constituent relations firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name constituent relations 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 1,135 constituent relations firms worldwide
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 3,751 reachable decision-makers.
Free signup · no credit card
Constituent relations firms worldwide at a glance
As of Sep 19, 2026Companies by employee count
Email recency is reported on each country list linked below.
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 constituent relations 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.
- Coverage
- Every country. Country and city lists for constituent relations firms are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “constituent relations 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 constituent relations 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 constituent relations firms, and records with no verified work email.
- 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, 3,751 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 19, 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.
Constituent relations firms by location
2 lists · largest firstEvery Constituent relations firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
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 constituent relations 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 constituent relations firms are there worldwide?
RevenueBase identified 1,135 constituent relations firms worldwide 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?
Mercury Public Affairs, LLC, headquartered in New York, tops this list with the largest team on record.
Which country has the most constituent relations firms?
The United States leads with 752 companies, followed by Canada (46). Every constituent relations firms list by country and city is linked on this page.
Which city has the most constituent relations firms?
Washington leads with 146 headquartered companies, followed by Sacramento (22) and New York (20).
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 3,751 verified decision-maker contacts tracked across these 1,135 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 19, 2026.
Ready to reach these companies? Verified emails and direct dials for all 1,135 constituent relations firms worldwide. Start with a free account, no credit card.
Download this list →Related lists
Browse the directory
Browse: Companies home · Lists by location · New lists
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.