Company lists · Data refreshed September 2026

Top 25 Biggest security companies based in the United States

Name: Biggest security companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 8,122 companies tracked

RevenueBase identified 8,122 biggest security companies headquartered in the United States as of September 2026 and tracks 286,084 professional contacts across them, including 79,800 with verified work emails. New York is the largest hub.

This list covers biggest security companies headquartered in the United States, 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 21, 2026.

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 21, 2026 86% judged on-target in blind review

8,122Companies

286,084Contacts tracked

79,800Verified emails

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The 25 largest biggest security companies based in the United States

Ranked by team size

Top 25 of 8,122 biggest security companies based in the United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to biggest security companies: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Securitas Security Services Usa, INC	Partial evidence	Parsippany, NJ, United StatesHQ checked Sep 21, 2026	10001+	38,634 contacts →
	Partial evidence “Securitas knows Security.” Source: RevenueBase Database · checked Sep 21, 2026
2	Palo Alto Networks	Indirect evidence	Santa Clara, CA, United StatesHQ checked Sep 21, 2026	10001+	18,431 contacts →
	Indirect 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 21, 2026
3	Fortinet	Indirect evidence	Sunnyvale, CA, United StatesHQ checked Sep 21, 2026	10001+	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 21, 2026
4	Symantec	Partial evidence	San Jose, CA, United StatesHQ checked Sep 21, 2026	10001+	11,169 contacts →
	Partial 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 21, 2026
5	Peraton	Indirect evidence	Reston, VA, United StatesHQ checked Sep 21, 2026	10001+	10,793 contacts →
	Indirect evidence “At Peraton, we're at the forefront of delivering the next big thing every day.” Source: RevenueBase Database · checked Sep 21, 2026
6	Mantech	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	5,001-10,000	9,697 contacts →
	Indirect evidence “MANTECH is more than a technology company.” Source: RevenueBase Database · checked Sep 21, 2026
7	Inter-Con Security	Partial evidence	Pasadena, CA, United StatesHQ checked Sep 21, 2026	10001+	3,612 contacts →
	Partial evidence “EVERYWHERE SECURITY MATTERS.” Source: RevenueBase Database · checked Sep 21, 2026
8	U.S. Security Associates, INC	Indirect evidence	Roswell, GA, United StatesHQ checked Sep 21, 2026	10001+	3,592 contacts →
	Indirect evidence “U.S.” Source: RevenueBase Database · checked Sep 21, 2026
9	Arctic Wolf	Indirect evidence	Eden Prairie, MN, United StatesHQ checked Sep 21, 2026	1,001-5,000	3,145 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 21, 2026
10	Security Industry Specialists	Partial evidence	Culver City, CA, United StatesHQ checked Sep 21, 2026	5,001-10,000	2,500 contacts →
	Partial 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 21, 2026
11	OPTIV	Indirect evidence	Leawood, KS, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
12	Paragon Systems INC	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	10001+	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 21, 2026
13	DMI	Indirect evidence	Mclean, VA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,683 contacts →
	Indirect evidence “DMI is a leading provider of digital services and technology solutions with a focus on end-to-end managed services, including managed mobility, cloud, cybersecurity, network…” Source: RevenueBase Database · checked Sep 21, 2026
14	Sunstates Security	Partial evidence	Raleigh, NC, United StatesHQ checked Sep 21, 2026	5,001-10,000	1,639 contacts →
	Partial evidence “Sunstates Security, LLC is one of the industry's leading providers of contract security services with a differentiated approach to providing successful, cost-effective, quality…” Source: RevenueBase Database · checked Sep 21, 2026
15	Forcepoint	Partial evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,636 contacts →
	Partial evidence “Forcepoint simplifies security for global businesses and governments.” Source: RevenueBase Database · checked Sep 21, 2026
16	Government Acquisitions	Indirect evidence	Cincinnati, OH, United StatesHQ checked Sep 21, 2026	n/a	1,440 contacts →
	Indirect evidence “Government Acquisitions, LLC (GAI) stands at the forefront of a transformative era, where artificial intelligence is reshaping our world and the stakes have never been higher.” Source: RevenueBase Database · checked Sep 21, 2026
17	Protection 1 Security Solutions	Partial evidence	Romeoville, IL, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,406 contacts →
	Partial evidence “As of May 2016, Protection 1 and ADT merged together to become the leading company in the electronic security industry.” Source: RevenueBase Database · checked Sep 21, 2026
18	Weiser Security Services, INC	Partial evidence	New Orleans, LA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,399 contacts →
	Partial evidence “Weiser Security Services is the 11th largest security service provider in the U.S.” Source: RevenueBase Database · checked Sep 21, 2026
19	Guardsmark	Partial evidence	New York, NY, United StatesHQ checked Sep 21, 2026	10001+	1,375 contacts →
	Partial evidence “Guardsmark, LLC provides security services.” Source: RevenueBase Database · checked Sep 21, 2026
20	Vector Security	Partial evidence	Warrendale, PA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,287 contacts →
	Partial evidence “Vector Security® has protected people and property by providing intelligent security solutions tailored to the needs of the customer for more than 50 years.” Source: RevenueBase Database · checked Sep 21, 2026
21	Thales Cybersecurity Products	Indirect evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,252 contacts →
	Indirect evidence “Thales is a global leader in cybersecurity, helping the most trusted organizations in the world protect their most critical applications, data, and identities anywhere at scale.” Source: RevenueBase Database · checked Sep 21, 2026
22	Guidepoint Security	Partial evidence	Reston, VA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,232 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 21, 2026
23	Imperva	Indirect evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	10001+	1,217 contacts →
	Indirect evidence “On Dec.” Source: RevenueBase Database · checked Sep 21, 2026
24	SOS Security LLC	Partial evidence	Parsippany, NJ, United StatesHQ checked Sep 21, 2026	10001+	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 21, 2026
25	Titan Security Group	Partial evidence	Chicago, IL, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,138 contacts →
	Partial evidence “At Titan Security Group, we understand that each client is unique, with specific security needs shaped by the type of property and its location.” Source: RevenueBase Database · checked Sep 21, 2026

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: biggest 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 biggest security companies.
Partial evidence: Its own public description names part of biggest security companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name biggest 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 8,122 biggest security companies based in the United States

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Biggest security companies based in the United States at a glance

As of Sep 21, 2026

27.9%Verified-email coverage

35.2Average contacts per company

1-10Median size (employees)

2.6%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

4,108

11-50

2,589

51-200

952

201-500

231

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 8,122 companies.

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 biggest 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.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “biggest 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 biggest 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 biggest security companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
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, 79,800 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 21, 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.

Biggest security companies by metro

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 biggest 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 biggest security companies are there based in the United States?

RevenueBase identified 8,122 biggest security companies headquartered in the United States 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 city has the most biggest security companies?

New York leads with 214 headquartered companies, followed by Houston (149) and Washington (143).

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 79,800 verified decision-maker contacts tracked across these 8,122 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 21, 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.