Company lists · Data refreshed September 2026

Top 25 Cybersecurity and physical security firms worldwide

RevenueBase identified 38,816 cybersecurity and physical security firms worldwide as of September 2026 and tracks 946,127 professional contacts across them, including 204,109 with verified work emails. The United States is the largest market and London the largest hub.

This list covers cybersecurity and physical 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 28, 2026. Country and city lists for cybersecurity and physical 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 28, 2026 86% judged on-target in blind review
38,816Companies
946,127Contacts tracked
204,109Verified emails
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The 25 largest cybersecurity and physical security firms worldwide

Ranked by team size
Top 25 of 38,816 cybersecurity and physical security firms worldwide, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to cybersecurity and physical 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
1Partial evidenceLondon, United KingdomHQ checked Sep 28, 202610001+79,699 contacts →

Partial 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 28, 2026
2Partial evidenceIrvine, CA, United StatesHQ checked Sep 28, 202610001+62,804 contacts →

Partial 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 28, 2026
3Indirect evidenceMadrid, SpainHQ checked Sep 28, 202610001+40,747 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
4Partial evidenceParsippany, NJ, United StatesHQ checked Sep 28, 202610001+38,634 contacts →

Partial evidence

“Securitas knows Security.”

Source: RevenueBase Database · checked Sep 28, 2026
5Partial evidenceSanta Clara, CA, United StatesHQ checked Sep 28, 202610001+18,431 contacts →

Partial evidence

“Palo Alto Networks, the global cybersecurity leader, is shaping the cloud-centric future with technology that is transforming the way people and organizations operate.”

Source: RevenueBase Database · checked Sep 28, 2026
6Indirect evidenceSunnyvale, CA, United StatesHQ checked Sep 28, 202610001+14,289 contacts →

Indirect evidence

“Fortinet makes possible a digital world that we can always trust through its mission to protect people, devices, and data everywhere.”

Source: RevenueBase Database · checked Sep 28, 2026
7Indirect evidenceUnited StatesHQ checked Sep 28, 2026n/a12,771 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026
8Strong evidenceSan Jose, CA, United StatesHQ checked Sep 28, 202610001+11,169 contacts →

Strong evidence

“Your backstage pass to the most epic cybersecurity solutions on the market for Endpoint, Network, Data and Cloud security.”

Source: RevenueBase Database · checked Sep 28, 2026
9Strong evidenceRemote, United StatesHQ checked Sep 28, 20265,001-10,00010,118 contacts →

Strong evidence

“CrowdStrike (Nasdaq: CRWD), a global cybersecurity leader, has redefined modern security with the world’s most advanced cloud-native platform for protecting critical areas of…”

Source: RevenueBase Database · checked Sep 28, 2026
10Indirect evidenceStockholm, SwedenHQ checked Sep 28, 202610001+6,335 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026
11Indirect evidenceHoffman Estates, IL, United StatesHQ checked Sep 28, 202610001+5,707 contacts →

Indirect evidence

“Convergint is a global systems integrator focused on delivering results for our customers through unparalleled service excellence.”

Source: RevenueBase Database · checked Sep 28, 2026
12Partial evidenceCork, IrelandHQ checked Sep 28, 202610001+5,384 contacts →

Partial 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 28, 2026
13Partial evidenceYoyogi, JapanHQ checked Sep 28, 20265,001-10,0004,942 contacts →

Partial evidence

“We’re a global cybersecurity leader, helping to make the world safe for exchanging digital information.”

Source: RevenueBase Database · checked Sep 28, 2026
14Partial evidenceAbingdon, United KingdomHQ checked Sep 28, 20265,001-10,0004,925 contacts →

Partial evidence

“Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.”

Source: RevenueBase Database · checked Sep 28, 2026
15Partial evidenceSingaporeHQ checked Sep 28, 202610001+4,610 contacts →

Partial evidence

“Certis is a leading advanced integrated security organisation that develops and delivers multi-disciplinary smart security and integrated services.”

Source: RevenueBase Database · checked Sep 28, 2026
16Partial evidenceIssy-les-moulineaux, FranceHQ checked Sep 28, 202610001+3,843 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
17Partial evidenceNanterre, FranceHQ checked Sep 28, 20261,001-5,0003,673 contacts →

Partial evidence

“Orange Cyberdefense is the expert cybersecurity business unit of the Orange Group.”

Source: RevenueBase Database · checked Sep 28, 2026
18Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 28, 2026n/a3,649 contacts →

Partial evidence

“We are a crowdsourced security company that safeguards organizations' assets from sophisticated threat actors before they can strike-by uniting our customers with trusted hackers…”

Source: RevenueBase Database · checked Sep 28, 2026
19Partial evidenceMadrid, SpainHQ checked Sep 28, 202610001+3,620 contacts →

Partial 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 28, 2026
20Indirect evidenceRoswell, GA, United StatesHQ checked Sep 28, 202610001+3,592 contacts →

Indirect evidence

“U.S.”

Source: RevenueBase Database · checked Sep 28, 2026
21Strong evidencePlano, TX, United StatesHQ checked Sep 28, 20261,001-5,0003,447 contacts →

Strong evidence

“Trellix is a global cybersecurity company delivering intelligence-led cyber resilience for security-conscious organizations at any stage of their journey.”

Source: RevenueBase Database · checked Sep 28, 2026
22Partial evidenceMilano, ItalyHQ checked Sep 28, 202610001+3,387 contacts →

Partial 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 28, 2026
23Indirect evidenceEden Prairie, MN, United StatesHQ checked Sep 28, 20261,001-5,0003,145 contacts →

Indirect evidence

“Every year new technologies, vendors, and solutions emerge-yet despite this constant innovation, high-profile breaches are all over the headlines.”

Source: RevenueBase Database · checked Sep 28, 2026
24Partial evidenceStockholm, SwedenHQ checked Sep 28, 20265,001-10,0003,004 contacts →

Partial evidence

“Securitas is a global knowledge leader in security.”

Source: RevenueBase Database · checked Sep 28, 2026
25Partial evidenceArlington, VA, United StatesHQ checked Sep 28, 20261,001-5,0002,933 contacts →

Partial evidence

“GTT is a leading networking and security as a service provider for multinational organizations, simply and securely connecting people and machines to data and applications –…”

Source: RevenueBase Database · checked Sep 28, 2026

Showing 25 of 38,816 cybersecurity and physical security firms worldwide

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Cybersecurity and physical security firms worldwide at a glance

As of Sep 28, 2026
21.6%Verified-email coverage
24.4Average contacts per company
11-50Median size (employees)
1.9%Largest-city concentration · London
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
19,292
11-50
13,163
51-200
4,011
201-500
1,115
501-1,000
454
1,001-5,000
451
5,001-10,000
98
10001+
104

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 cybersecurity and physical 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
Every country. Country and city lists for cybersecurity and physical security firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “cybersecurity and physical 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 cybersecurity and physical 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 cybersecurity and physical 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, 204,109 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 28, 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.

Cybersecurity and physical security firms by location

218 lists · largest first

Every Cybersecurity and physical 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 cybersecurity and physical 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 cybersecurity and physical security firms are there worldwide?

RevenueBase identified 38,816 cybersecurity and physical 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 cybersecurity and physical security firms?

The United States leads with 8,883 companies, followed by India (2,695) and the United Kingdom (2,327). Every cybersecurity and physical security firms list by country and city is linked on this page.

Which city has the most cybersecurity and physical security firms?

London leads with 725 headquartered companies, followed by Sao Paulo (449) and Dubai (335).

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 204,109 verified decision-maker contacts tracked across these 38,816 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 28, 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.