Company lists · Data refreshed September 2026

Top 25 Critical infrastructure security services worldwide

RevenueBase identified 12,076 critical infrastructure security services worldwide as of September 2026 and tracks 264,935 professional contacts across them, including 47,791 with verified work emails. The United States is the largest market and London the largest hub.

This list covers critical infrastructure security services 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 27, 2026. Country and city lists for critical infrastructure security services 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 27, 2026 86% judged on-target in blind review
12,076Companies
264,935Contacts tracked
47,791Verified emails
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The 25 largest critical infrastructure security services worldwide

Ranked by team size
Top 25 of 12,076 critical infrastructure security services worldwide, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to critical infrastructure security services: 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 evidenceParsippany, NJ, United StatesHQ checked Sep 27, 202610001+38,634 contacts →

Partial evidence

“Securitas knows Security.”

Source: RevenueBase Database · checked Sep 27, 2026
2Indirect evidenceUnited StatesHQ checked Sep 27, 2026n/a12,771 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 27, 2026
3Partial evidenceMadrid, SpainHQ checked Sep 27, 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 27, 2026
4Indirect evidenceRoswell, GA, United StatesHQ checked Sep 27, 202610001+3,592 contacts →

Indirect evidence

“U.S.”

Source: RevenueBase Database · checked Sep 27, 2026
5Partial evidenceMilano, ItalyHQ checked Sep 27, 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 27, 2026
6Partial evidenceStockholm, SwedenHQ checked Sep 27, 20265,001-10,0003,004 contacts →

Partial evidence

“Securitas is a global knowledge leader in security.”

Source: RevenueBase Database · checked Sep 27, 2026
7Strong evidenceWarwick, United KingdomHQ checked Sep 27, 20261,001-5,0002,407 contacts →

Strong evidence

“Telent designs, builds, manages, and maintains the nation’s critical infrastructure technology that keeps the country moving, connected, and safe.”

Source: RevenueBase Database · checked Sep 27, 2026
8Indirect evidenceLeawood, KS, United StatesHQ checked Sep 27, 20261,001-5,0002,222 contacts →

Indirect evidence

“Optiv is the cyber advisory and solutions leader, delivering strategic and technical expertise to nearly companies across every major industry.”

Source: RevenueBase Database · checked Sep 27, 2026
9Indirect evidenceAnnapolis, MD, United StatesHQ checked Sep 27, 20261,001-5,0002,025 contacts →

Indirect evidence

“Crisis24, a GardaWorld company, is widely regarded as the leading integrated risk management, crisis response, consulting, and global protective solutions firm, serving the…”

Source: RevenueBase Database · checked Sep 27, 2026
10Partial evidenceHerndon, VA, United StatesHQ checked Sep 27, 202610001+1,949 contacts →

Partial evidence

“Paragon Systems employs over 10,500 professionals in specialized operations providing security, fire, investigations, inspections, cybersecurity, risk management, and mission…”

Source: RevenueBase Database · checked Sep 27, 2026
11Indirect evidenceNorth York, ON, CanadaHQ checked Sep 27, 20265,001-10,0001,632 contacts →

Indirect evidence

“Over 90 years of protecting the things that matter, we’ve seen more than most.”

Source: RevenueBase Database · checked Sep 27, 2026
12Partial evidenceBp12936, FranceHQ checked Sep 27, 202610001+1,455 contacts →

Partial evidence

“ICTS Europe is Europe’s leading security specialist.”

Source: RevenueBase Database · checked Sep 27, 2026
13Indirect evidenceLeatherhead, United KingdomHQ checked Sep 27, 20261,001-5,0001,437 contacts →

Indirect evidence

“With offices in the UK and Australia, Frazer-Nash is a leading systems, engineering and technology company.”

Source: RevenueBase Database · checked Sep 27, 2026
14Indirect evidenceBlagnac, FranceHQ checked Sep 27, 20261,001-5,0001,431 contacts →

Indirect evidence

“Airbus Protect is an Airbus subsidiary bringing together expertise in cybersecurity, safety and sustainability-related services.”

Source: RevenueBase Database · checked Sep 27, 2026
15Indirect evidenceDiegem, BelgiumHQ checked Sep 27, 20265,001-10,0001,419 contacts →

Indirect evidence

“See a different world.”

Source: RevenueBase Database · checked Sep 27, 2026
16Indirect evidenceAl Nakheel, Saudi ArabiaHQ checked Sep 27, 2026501-1,0001,378 contacts →

Indirect evidence

“We are established for enriching local content in designing, developing, and operating secure digital computing environments through Saudi talents, by fulfilling our role as a…”

Source: RevenueBase Database · checked Sep 27, 2026
17Partial evidenceNew York, NY, United StatesHQ checked Sep 27, 202610001+1,375 contacts →

Partial evidence

“Guardsmark, LLC provides security services.”

Source: RevenueBase Database · checked Sep 27, 2026
18Partial evidenceDubai, United Arab EmiratesHQ checked Sep 27, 20265,001-10,0001,374 contacts →

Partial evidence

“First Security Group LLC was founded in 2004 with the vision of His Highness, the Vice President, Prime Minister, and Ruler of Dubai, Sheikh Mohamed bin Rashid Al Maktoum.”

Source: RevenueBase Database · checked Sep 27, 2026
19Indirect evidenceSão Paulo, BrazilHQ checked Sep 27, 20265,001-10,0001,361 contacts →

Indirect evidence

“O Grupo Comando G8 é referência nacional na implantação e operação de soluções integradas em segurança e serviços.”

Source: RevenueBase Database · checked Sep 27, 2026
20Partial evidenceWoodmead, South AfricaHQ checked Sep 27, 202610001+1,340 contacts →

Partial evidence

“At Imvula Quality Protection, we don’t just provide security, we create peace of mind.”

Source: RevenueBase Database · checked Sep 27, 2026
21Partial evidenceReston, VA, United StatesHQ checked Sep 27, 20261,001-5,0001,232 contacts →

Partial evidence

“GuidePoint Security provides trusted cybersecurity expertise, solutions, and services that help organizations make informed decisions and minimize risk.”

Source: RevenueBase Database · checked Sep 27, 2026
22Indirect evidenceMorrisville, NC, United StatesHQ checked Sep 27, 2026501-1,0001,175 contacts →

Indirect evidence

“IEM is a professional services firm dedicated to building a safe, secure, and resilient world.”

Source: RevenueBase Database · checked Sep 27, 2026
23Partial evidenceParsippany, NJ, United StatesHQ checked Sep 27, 202610001+1,151 contacts →

Partial evidence

“SOS Security is a known innovator and leader in the security and protective services industry.”

Source: RevenueBase Database · checked Sep 27, 2026
24Indirect evidencePittsburgh, PA, United StatesHQ checked Sep 27, 20265,001-10,0001,062 contacts →

Indirect evidence

“Founded in 1982, St.”

Source: RevenueBase Database · checked Sep 27, 2026
25Partial evidencePearl River, NY, United StatesHQ checked Sep 27, 20265,001-10,0001,050 contacts →

Partial evidence

“Brosnan Risk Consultants, Ltd.(BRC) is a security risk management firm focusing on physical security, emergency security, disaster preparedness and recovery and management…”

Source: RevenueBase Database · checked Sep 27, 2026

Showing 25 of 12,076 critical infrastructure security services worldwide

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Critical infrastructure security services worldwide at a glance

As of Sep 27, 2026
18.0%Verified-email coverage
21.9Average contacts per company
1-10Median size (employees)
2.0%Largest-city concentration · London
Sep 27, 2026Page data refreshed

Companies by employee count

1-10
6,123
11-50
3,720
51-200
1,326
201-500
427
501-1,000
181
1,001-5,000
197
5,001-10,000
38
10001+
37

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 critical infrastructure security services, 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 critical infrastructure security services are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “critical infrastructure security services”. 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 critical infrastructure security services), 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 critical infrastructure security services, 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, 47,791 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 27, 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.

Critical infrastructure security services by location

84 lists · largest first

Every Critical infrastructure security services 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 critical infrastructure security services, 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 critical infrastructure security services are there worldwide?

RevenueBase identified 12,076 critical infrastructure security services 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?

Securitas Security Services Usa, INC, headquartered in Parsippany, tops this list with the largest team on record.

Which country has the most critical infrastructure security services?

The United States leads with 2,925 companies, followed by the United Kingdom (726) and India (555). Every critical infrastructure security services list by country and city is linked on this page.

Which city has the most critical infrastructure security services?

London leads with 243 headquartered companies, followed by Sao Paulo (155) and Paris (113).

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 47,791 verified decision-maker contacts tracked across these 12,076 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 27, 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.