Company lists · Data refreshed September 2026

Top 25 Defence cybersecurity companies based in the United States

Name: Defence cybersecurity 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 3,728 companies tracked

RevenueBase identified 3,728 defence cybersecurity companies headquartered in the United States as of September 2026 and tracks 334,596 professional contacts across them, including 75,771 with verified work emails. New York is the largest hub.

This list covers defence cybersecurity 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

3,728Companies

334,596Contacts tracked

75,771Verified emails

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The 25 largest defence cybersecurity companies based in the United States

Ranked by team size

Top 25 of 3,728 defence cybersecurity 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 defence cybersecurity 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	Northrop Grumman	Indirect evidence	Falls Church, VA, United StatesHQ checked Sep 21, 2026	10001+	74,984 contacts →
	Indirect evidence “We are a close-knit community of big thinkers collaborating to keep the world safe.” Source: RevenueBase Database · checked Sep 21, 2026
2	L3harris Technologies	Partial evidence	Melbourne, FL, United StatesHQ checked Sep 21, 2026	10001+	24,855 contacts →
	Partial evidence “L3Harris Technologies is the Trusted Disruptor in the defense industry.” Source: RevenueBase Database · checked Sep 21, 2026
3	Parsons Corporation	Partial evidence	Chantilly, VA, United StatesHQ checked Sep 21, 2026	10001+	19,456 contacts →
	Partial evidence “Founded in 1944, Parsons Corporation, a digitally enabled solutions provider, is focused on creating the future of the defense, intelligence, and critical infrastructure markets.” Source: RevenueBase Database · checked Sep 21, 2026
4	Palo Alto Networks	Partial evidence	Santa Clara, CA, United StatesHQ checked Sep 21, 2026	10001+	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 21, 2026
5	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
6	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
7	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
8	Crowdstrike	Partial evidence	Remote, United StatesHQ checked Sep 21, 2026	5,001-10,000	10,118 contacts →
	Partial 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 21, 2026
9	Sierra Nevada Corporation	Indirect evidence	Sparks, NV, United StatesHQ checked Sep 21, 2026	1,001-5,000	4,484 contacts →
	Indirect evidence “SNC is a trusted global leader in aerospace and national security.” Source: RevenueBase Database · checked Sep 21, 2026
10	Bugcrowd	Indirect evidence	San Francisco, CA, United StatesHQ checked Sep 21, 2026	n/a	3,649 contacts →
	Indirect 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 21, 2026
11	Trellix	Partial evidence	Plano, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	3,447 contacts →
	Partial 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 21, 2026
12	Sentinelone	Partial evidence	Mountain View, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	3,052 contacts →
	Partial evidence “SentinelOne is the world's leading AI-powered cybersecurity platform.” Source: RevenueBase Database · checked Sep 21, 2026
13	Rapid7	Partial evidence	Boston, MA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,822 contacts →
	Partial evidence “Rapid7, Inc.(NASDAQ: RPD) is a global leader in AI-powered managed cybersecurity operations, trusted to advance organizations’ cyber resilience.” Source: RevenueBase Database · checked Sep 21, 2026
14	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
15	Barracuda	Partial evidence	Campbell, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,157 contacts →
	Partial evidence “Barracuda is a leading global cybersecurity company providing complete protection against complex threats for all size business.” Source: RevenueBase Database · checked Sep 21, 2026
16	Fortra	Partial evidence	Eden Prairie, MN, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,648 contacts →
	Partial evidence “Fortra delivers AI-amplified cybersecurity solutions that help organizations use and protect data with confidence.” Source: RevenueBase Database · checked Sep 21, 2026
17	Dynetics, INC	Partial evidence	Huntsville, AL, United StatesHQ checked Sep 21, 2026	10001+	1,532 contacts →
	Partial 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 21, 2026
18	Thales Cybersecurity Products	Partial evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,252 contacts →
	Partial 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
19	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
20	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
21	Opswat	Indirect evidence	Tampa, FL, United StatesHQ checked Sep 21, 2026	501-1,000	1,119 contacts →
	Indirect evidence “OPSWAT protects critical infrastructure.” Source: RevenueBase Database · checked Sep 21, 2026
22	Agile Defense	Partial evidence	Mclean, VA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,086 contacts →
	Partial evidence “Agile Defense: Always Evolving Agile Defense stands at the forefront of innovation, driving advanced capabilities and solutions tailored to the most critical national security and…” Source: RevenueBase Database · checked Sep 21, 2026
23	Watchguard Technologies	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,059 contacts →
	Indirect evidence “WatchGuard® Technologies, Inc.” Source: RevenueBase Database · checked Sep 21, 2026
24	Radiance Technologies	Indirect evidence	Huntsville, AL, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,049 contacts →
	Indirect evidence “Radiance Technologies, Inc.” Source: RevenueBase Database · checked Sep 21, 2026
25	PPC	Indirect evidence	Trevose, PA, United StatesHQ checked Sep 21, 2026	201-500	979 contacts →
	Indirect evidence “PPC is now part of DSA” 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: defence cybersecurity 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 defence cybersecurity companies.
Partial evidence: Its own public description names part of defence cybersecurity companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name defence cybersecurity 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 3,728 defence cybersecurity companies based in the United States

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Defence cybersecurity companies based in the United States at a glance

As of Sep 21, 2026

22.6%Verified-email coverage

89.8Average contacts per company

11-50Median size (employees)

2.7%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

1,760

11-50

1,231

51-200

485

201-500

120

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 3,728 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 defence cybersecurity 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 “defence cybersecurity 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 defence cybersecurity 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 defence cybersecurity 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, 75,771 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.

Defence cybersecurity 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 defence cybersecurity 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 defence cybersecurity companies are there based in the United States?

RevenueBase identified 3,728 defence cybersecurity 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?

Northrop Grumman, headquartered in Falls Church, tops this list with the largest team on record.

Which city has the most defence cybersecurity companies?

New York leads with 101 headquartered companies, followed by Washington (87) and Austin (71).

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 75,771 verified decision-maker contacts tracked across these 3,728 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.