Company lists · Data refreshed September 2026

Top 25 Security firms worldwide

RevenueBase identified 27,543 security firms worldwide as of September 2026 and tracks 897,946 professional contacts across them, including 74,050 with verified work emails and 105,345 with mobile numbers. The United States is the largest market and London the largest hub.

This list covers security 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 6, 2026. Country and city lists for security 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 6, 2026 86% judged on-target in blind review
27,543Companies
897,946Contacts tracked
74,050Verified emails
105,345Mobile numbers
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The 25 largest security firms worldwide

Ranked by team size
Top 25 of 27,543 security firms worldwide, ranked by team size, largest first. Data refreshed Sep 6, 2026. RevenueBase Smart Search rates how each company's information relates to security firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Strong evidenceLondon, United KingdomHQ checked Sep 6, 202610001+79,699 contacts →

Strong evidence

“G4S is a leading security and facility services company that provides proactive security services and cutting-edge smart technology to deliver tailored, integrated security…”

Source: RevenueBase Database · checked Sep 6, 2026
2Strong evidenceIrvine, CA, United StatesHQ checked Sep 6, 202610001+62,804 contacts →

Strong evidence

“Allied Universal®, a leading security and facility services company, provides proactive security services and cutting-edge smart technology to deliver evolving, tailored solutions…”

Source: RevenueBase Database · checked Sep 6, 2026
3Indirect evidenceMadrid, SpainHQ checked Sep 6, 202610001+40,747 contacts →

Indirect evidence

“50 Years of Excellence: Experience, Innovation, and Commitment to Safety.”

Source: RevenueBase Database · checked Sep 6, 2026
4Strong evidenceParsippany, NJ, United StatesHQ checked Sep 6, 202610001+38,634 contacts →

Strong evidence

“Securitas knows Security.”

Source: RevenueBase Database · checked Sep 6, 2026
5Strong evidenceSaint-laurent, CanadaHQ checked Sep 6, 202610001+17,041 contacts →

Strong evidence

“GardaWorld is the world’s largest privately-owned security services company, offering cash services, physical and specialized security solutions, and with our Crisis24 portal, the…”

Source: RevenueBase Database · checked Sep 6, 2026
6Strong evidenceGlobal Hq - Versoix, GermanyHQ checked Sep 6, 202610001+14,199 contacts →

Strong evidence

“Verisure is the global leader in professionally monitored security services by customers served, with a market-leading presence across Europe and Latin America.”

Source: RevenueBase Database · checked Sep 6, 2026
7Strong evidenceSao Paulo, BrazilHQ checked Sep 6, 202610001+7,986 contacts →

Strong evidence

“One of the largest companies in the professional services and security markets in Brazil.”

Source: RevenueBase Database · checked Sep 6, 2026
8Indirect evidenceStockholm, SwedenHQ checked Sep 6, 202610001+6,335 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 6, 2026
9Strong evidenceCork, IrelandHQ checked Sep 6, 202610001+5,384 contacts →

Strong evidence

“Tyco offers comprehensive security solutions to protect people, facilities, and assets as part of Johnson Controls world leading portfolio of building products, technologies…”

Source: RevenueBase Database · checked Sep 6, 2026
10Strong evidenceBurnaby, BC, CanadaHQ checked Sep 6, 202610001+4,835 contacts →

Strong evidence

“As one of Canada’s Best Managed Companies, boasting Canada’s 10 Most Admired Corporate Cultures, Paladin is Canada’s leading security company, with services and superior expertise…”

Source: RevenueBase Database · checked Sep 6, 2026
11Indirect evidenceBarueri, BrazilHQ checked Sep 6, 202610001+4,572 contacts →

Indirect evidence

“A Graber atua de forma pioneira na prestação de serviços de segurança desde 1982, introduzindo o conceito de projetos integrados na área de segurança.”

Source: RevenueBase Database · checked Sep 6, 2026
12Indirect evidenceSao Paulo, BrazilHQ checked Sep 6, 202610001+4,530 contacts →

Indirect evidence

“A SegurPro é o próximo passo em segurança privada.”

Source: RevenueBase Database · checked Sep 6, 2026
13Indirect evidenceSao Paulo, BrazilHQ checked Sep 6, 202610001+4,292 contacts →

Indirect evidence

“O que é trabalhar no Grupo Haganá?”

Source: RevenueBase Database · checked Sep 6, 2026
14Strong evidenceSt. Petersburg, FL, United StatesHQ checked Sep 6, 2026n/a4,038 contacts →

Strong evidence

“Excelsior Defense is a security and investigations company based out of St.”

Source: RevenueBase Database · checked Sep 6, 2026
15Indirect evidenceNorthridge, CA, United StatesHQ checked Sep 6, 202610001+4,025 contacts →

Indirect evidence

“Contemporary Services Corporation (CSC) is recognized worldwide as the pioneer, expert and only employee owned company in the crowd management field.”

Source: RevenueBase Database · checked Sep 6, 2026
16Strong evidenceIssy-les-moulineaux, FranceHQ checked Sep 6, 202610001+3,843 contacts →

Strong evidence

“Securitas vous apporte son savoir‑faire et ses compétences dans la sécurisation de votre entreprise.”

Source: RevenueBase Database · checked Sep 6, 2026
17Strong evidenceMadrid, SpainHQ checked Sep 6, 202610001+3,620 contacts →

Strong evidence

“Securitas, Soluciones de Seguridad a medida Nuestro liderazgo en conocimientos de seguridad nos ha permitido desarrollar una estrategia basada en tres pilares fundamentales…”

Source: RevenueBase Database · checked Sep 6, 2026
18Strong evidencePasadena, CA, United StatesHQ checked Sep 6, 202610001+3,612 contacts →

Strong evidence

“EVERYWHERE SECURITY MATTERS.”

Source: RevenueBase Database · checked Sep 6, 2026
19Indirect evidenceRoswell, GA, United StatesHQ checked Sep 6, 202610001+3,592 contacts →

Indirect evidence

“U.S.”

Source: RevenueBase Database · checked Sep 6, 2026
20Strong evidenceMilano, ItalyHQ checked Sep 6, 202610001+3,387 contacts →

Strong evidence

“Il Gruppo Sicuritalia, con oltre 18.500 dipendenti, è la più grande azienda italiana ed il secondo player privato europeo in ambito Security.”

Source: RevenueBase Database · checked Sep 6, 2026
21Indirect evidenceLima, PeruHQ checked Sep 6, 202610001+3,140 contacts →

Indirect evidence

“Somos la empresa de seguridad de mayor prestigio en el Perú" Comenzamos en el año 1989, con solo 4 hombres de Seguridad, que creyeron en nuestro estilo de liderazgo y decidieron…”

Source: RevenueBase Database · checked Sep 6, 2026
22Strong evidenceStockholm, SwedenHQ checked Sep 6, 20265,001-10,0003,004 contacts →

Strong evidence

“Securitas is a global knowledge leader in security.”

Source: RevenueBase Database · checked Sep 6, 2026
23Indirect evidenceSão Paulo, BrazilHQ checked Sep 6, 202610001+2,772 contacts →

Indirect evidence

“Fundado em 1992, o GRUPO GR se consolidou no mercado por sua qualidade e seriedade na implantação e operação de soluções de segurança e serviços para diversos tipos de clientes.”

Source: RevenueBase Database · checked Sep 6, 2026
24Strong evidenceCulver City, CA, United StatesHQ checked Sep 6, 20265,001-10,0002,500 contacts →

Strong evidence

“The industry leader in security, Security Industry Specialists offers unique solutions to Fortune 500 companies, international events, and celebrity clients.”

Source: RevenueBase Database · checked Sep 6, 2026
25Indirect evidenceSão José, BrazilHQ checked Sep 6, 20265,001-10,0002,462 contacts →

Indirect evidence

“A Orsegups atua desde 1977 na prestação de serviços de segurança e terceirização de serviços especializados.”

Source: RevenueBase Database · checked Sep 6, 2026

Showing 25 of 27,543 security firms worldwide

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Security firms worldwide at a glance

As of Sep 6, 2026
8.2%Verified-email coverage
11.7%Mobile-number coverage
32.6Average contacts per company
11-50Median size (employees)
2.8%Largest-city concentration · London
Sep 6, 2026Page data refreshed

Companies by employee count

1-10
9,691
11-50
8,499
51-200
4,951
201-500
1,927
501-1,000
986
1,001-5,000
917
5,001-10,000
182
10001+
150

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 security 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
47 countries, largest first: the United States, the United Kingdom, Brazil, France, India, Canada, Germany, Italy, Australia, the Netherlands and 37 more. Country and city lists for security firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “security 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 security 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 security 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, 74,050 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 between September 6, 2026 and September 14, 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.

Security firms by location

119 lists · largest first

Every Security firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 security 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 security firms are there worldwide?

RevenueBase identified 27,543 security 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?

G4s, headquartered in London, tops this list with the largest team on record.

Which country has the most security firms?

The United States leads with 6,852 companies, followed by the United Kingdom (3,630) and Brazil (2,190). Every security firms list by country and city is linked on this page.

Which city has the most security firms?

London leads with 759 headquartered companies, followed by Sao Paulo (426) and New York (189).

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 74,050 verified decision-maker contacts tracked across these 27,543 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled from the company graph between September 6, 2026 and September 14, 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.