Company lists · Data refreshed September 2026
Top 25 Critical infrastructure security companies worldwide
RevenueBase identified 14,494 critical infrastructure security companies worldwide as of September 2026 and tracks 455,585 professional contacts across them, including 72,486 with verified work emails. The United States is the largest market and London the largest hub.
This list covers critical infrastructure security companies 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 companies 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 critical infrastructure security companies worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 38,634 contacts → | ||||
Partial evidence “Securitas knows Security.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 12,771 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 9,697 contacts → | ||||
Indirect evidence “MANTECH is more than a technology company.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 6,335 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 4,530 contacts → | ||||
Indirect evidence “A SegurPro é o próximo passo em segurança privada.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 4,038 contacts → | ||||
Partial evidence “Excelsior Defense is a security and investigations company based out of St.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 3,673 contacts → | ||||
Indirect evidence “Orange Cyberdefense is the expert cybersecurity business unit of the Orange Group.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 3,592 contacts → | ||||
Indirect evidence “U.S.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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, 2026Thanks. The Data Team will review it. | |||||
| 12 | 3,004 contacts → | ||||
Partial evidence “Securitas is a global knowledge leader in security.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 2,222 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, 2026Thanks. The Data Team will review it. | |||||
| 14 | 2,165 contacts → | ||||
Indirect evidence “Com mais de 8 mil colaboradores, presente em 11 estados, vencedora do Prêmio Valor Carreira por sete vezes consecutivas, certificada pela GPTW e única empresa brasileira membro do…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 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, 2026Thanks. The Data Team will review it. | |||||
| 16 | 1,813 contacts → | ||||
Partial evidence “At Wilson Security, we are committed to building a safer future for everyone.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 1,727 contacts → | ||||
Indirect evidence “HSS is now Tarian!” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 1,632 contacts → | ||||
Indirect evidence “Over 90 years of protecting the things that matter, we’ve seen more than most.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 1,532 contacts → | ||||
Strong evidence “Leidos Dynetics provides responsive, cost-effective engineering, scientific, IT solutions to the national security, cybersecurity, space, and critical infrastructure sectors.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 1,455 contacts → | ||||
Partial evidence “ICTS Europe is Europe’s leading security specialist.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 1,419 contacts → | ||||
Indirect evidence “See a different world.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 1,399 contacts → | ||||
Partial evidence “Weiser Security Services is the 11th largest security service provider in the U.S.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 1,378 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, 2026Thanks. The Data Team will review it. | |||||
| 24 | 1,375 contacts → | ||||
Partial evidence “Guardsmark, LLC provides security services.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 1,374 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, 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: critical infrastructure security companies. 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 critical infrastructure security companies.
- Partial evidence
- Its own public description names part of critical infrastructure security companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name critical infrastructure security companies. 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 14,494 critical infrastructure security companies worldwide
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Critical infrastructure security companies worldwide at a glance
As of Sep 27, 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 critical infrastructure security companies, 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 companies are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “critical infrastructure security companies”. 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 companies), 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 companies, 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, 72,486 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 companies by location
103 lists · largest firstEvery Critical infrastructure security companies list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Critical infrastructure security companies based in the United States3,610
- Critical infrastructure security companies based in the United Kingdom894
- Critical infrastructure security companies based in India884
- Critical infrastructure security companies based in France512
- Critical infrastructure security companies based in Brazil476
- Critical infrastructure security companies based in Australia469
- Critical infrastructure security companies based in Canada468
- Critical infrastructure security companies based in Germany335
- Critical infrastructure security companies based in Mexico264
- Critical infrastructure security companies based in the United Arab Emirates236
- Critical infrastructure security companies based in the Netherlands234
- Critical infrastructure security companies based in South Africa219
- Critical infrastructure security companies based in Spain217
- Critical infrastructure security companies based in Italy216
- Critical infrastructure security companies based in Colombia159
- Critical infrastructure security companies based in Argentina145
- Critical infrastructure security companies based in Chile145
- Critical infrastructure security companies based in Türkiye133
- Critical infrastructure security companies based in Israel126
- Critical infrastructure security companies based in Saudi Arabia117
- Critical infrastructure security companies based in Switzerland103
- Critical infrastructure security companies based in Peru101
- Critical infrastructure security companies based in Nigeria99
- Critical infrastructure security companies based in Belgium98
- Critical infrastructure security companies based in Sweden98
- Critical infrastructure security companies based in Pakistan94
- Critical infrastructure security companies based in Poland87
- Critical infrastructure security companies based in Indonesia71
- Critical infrastructure security companies based in Malaysia68
- Critical infrastructure security companies based in Kenya64
- Critical infrastructure security companies based in New Zealand62
- Critical infrastructure security companies based in Egypt61
- Critical infrastructure security companies based in Romania61
- Critical infrastructure security companies based in Ecuador50
- Critical infrastructure security companies based in Qatar50
- Critical infrastructure security companies based in Greece49
- Critical infrastructure security companies based in Ireland44
- Critical infrastructure security companies based in Portugal38
- Critical infrastructure security companies based in Ukraine38
- Critical infrastructure security companies based in Denmark37
- Critical infrastructure security companies based in Austria34
- Critical infrastructure security companies based in Hungary28
- Critical infrastructure security companies based in Finland27
- Critical infrastructure security companies based in Norway25
Cities
- Critical infrastructure security companies based in London, United Kingdom304
- Critical infrastructure security companies based in Sao Paulo, Brazil149
- Critical infrastructure security companies based in Dubai, United Arab Emirates134
- Critical infrastructure security companies based in Paris, France107
- Critical infrastructure security companies based in New York, United States101
- Critical infrastructure security companies based in Toronto, Canada92
- Critical infrastructure security companies based in Houston, United States81
- Critical infrastructure security companies based in Washington, United States80
- Critical infrastructure security companies based in Melbourne, Australia77
- Critical infrastructure security companies based in New Delhi, India74
- Critical infrastructure security companies based in Sydney, Australia71
- Critical infrastructure security companies based in Hyderabad, India67
- Critical infrastructure security companies based in Riyadh, Saudi Arabia66
- Critical infrastructure security companies based in Los Angeles, United States59
- Critical infrastructure security companies based in Miami, United States59
- Critical infrastructure security companies based in Mumbai, India59
- Critical infrastructure security companies based in Pune, India58
- Critical infrastructure security companies based in Nairobi, Kenya57
- Critical infrastructure security companies based in Bogota, Colombia55
- Critical infrastructure security companies based in Madrid, Spain53
- Critical infrastructure security companies based in Atlanta, United States51
- Critical infrastructure security companies based in Bangalore, India51
- Critical infrastructure security companies based in Chicago, United States49
- Critical infrastructure security companies based in Istanbul, Türkiye49
- Critical infrastructure security companies based in Dallas, United States48
- Critical infrastructure security companies based in Santiago, Chile47
- Critical infrastructure security companies based in Austin, United States45
- Critical infrastructure security companies based in Chennai, India45
- Critical infrastructure security companies based in Johannesburg, South Africa45
- Critical infrastructure security companies based in Bengaluru, India43
- Critical infrastructure security companies based in Montreal, Canada43
- Critical infrastructure security companies based in Stockholm, Sweden43
- Critical infrastructure security companies based in Berlin, Germany40
- Critical infrastructure security companies based in Ottawa, Canada40
- Critical infrastructure security companies based in Arlington, United States39
- Critical infrastructure security companies based in Columbia, United States37
- Critical infrastructure security companies based in Ahmedabad, India36
- Critical infrastructure security companies based in Tampa, United States35
- Critical infrastructure security companies based in Calgary, Canada34
- Critical infrastructure security companies based in Herndon, United States34
- Critical infrastructure security companies based in Rio De Janeiro, Brazil34
- Critical infrastructure security companies based in Alexandria, United States31
- Critical infrastructure security companies based in Brisbane, Australia31
- Critical infrastructure security companies based in Charlotte, United States31
- Critical infrastructure security companies based in Denver, United States31
- Critical infrastructure security companies based in Doha, Qatar30
- Critical infrastructure security companies based in Reston, United States28
- Critical infrastructure security companies based in San Francisco, United States28
- Critical infrastructure security companies based in Baltimore, United States27
- Critical infrastructure security companies based in Mclean, United States27
- Critical infrastructure security companies based in Perth, Australia27
- Critical infrastructure security companies based in San Antonio, United States27
- Critical infrastructure security companies based in Abu Dhabi, United Arab Emirates26
- Critical infrastructure security companies based in Quito, Ecuador26
- Critical infrastructure security companies based in Tel Aviv, Israel26
- Critical infrastructure security companies based in Warszawa, Poland26
- Critical infrastructure security companies based in Canberra, Australia25
- Critical infrastructure security companies based in Las Vegas, United States25
- Critical infrastructure security companies based in Phoenix, United States25
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 companies, 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 companies are there worldwide?
RevenueBase identified 14,494 critical infrastructure security companies 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?
Allied Universal, headquartered in Irvine, tops this list with the largest team on record.
Which country has the most critical infrastructure security companies?
The United States leads with 3,610 companies, followed by the United Kingdom (894) and India (884). Every critical infrastructure security companies list by country and city is linked on this page.
Which city has the most critical infrastructure security companies?
London leads with 309 headquartered companies, followed by Sao Paulo (149) and Dubai (134).
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 72,486 verified decision-maker contacts tracked across these 14,494 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.