Company lists · Data verified August 2026

Top 25 Defense cybersecurity companies based in the United States

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

Compiled by the RevenueBase Data Team Verified Aug 28, 2026 3,288 companies tracked

There are 3,288 defense cybersecurity companies headquartered in the United States (RevenueBase, August 2026). RevenueBase tracks 245,980 professional contacts across them, including 31,764 with verified work emails and 108,177 with mobile numbers. Washington is the largest hub.

This list covers defense 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. Data current as of August 28, 2026.

3,288Companies

245,980Contacts tracked

31,764Verified emails

108,177Mobile numbers

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The 25 largest defense cybersecurity companies based in the United States

Ranked by team size

Top 25 of 3,288 defense cybersecurity companies based in the United States, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	Northrop Grumman	San Diego, CA	10001+	75,000	1,247
2	Booz Allen Hamilton	Mclean, VA	10001+	34,223	1
3	L3harris Technologies	Melbourne, FL	10001+	24,757	932
4	Symantec	San Jose, CA	10001+	11,179	876
5	Peraton	San Diego, CA	10001+	10,741	197
6	Sierra Nevada Corporation	Sparks, NV	1,001-5,000	4,442	81
7	Trellix	Plano, TX	1,001-5,000	3,490	1,633
8	OPTIV	Chantilly, VA	1,001-5,000	2,206	1,422
9	Bitdefender	Fort Lauderdale, FL	1,001-5,000	2,141	1,230
10	Barracuda	Alpharetta, GA	1,001-5,000	2,108	1,463
11	Fortra	Eden Prairie, MN	1,001-5,000	1,640	1,037
12	Dynetics, INC	Huntsville, AL	10001+	1,533	41
13	Thales Cybersecurity Products	Austin, TX	1,001-5,000	1,252	645
14	Guidepoint Security	Tampa, FL	1,001-5,000	1,234	809
15	Imperva	Austin, TX	10001+	1,211	829
16	Agile Defense	Huntsville, AL	1,001-5,000	1,080	402
17	Radiance Technologies	Baton Rouge, LA	1,001-5,000	1,037	19
18	Tyto Athene, LLC	Amherst, VA	1,001-5,000	858	16
19	STR	Arlington, VA	501-1,000	759	24
20	TWO SIX Technologies	Austin, TX	501-1,000	648	435
21	Telos Corporation	Las Vegas, NV	501-1,000	636	230
22	Planned Systems International	Valparaiso, FL	1,001-5,000	608	316
23	Applied Research Solutions	Boston, MA	501-1,000	595	18
24	By Light Professional IT Services	Arlington, VA	1,001-5,000	562	280
25	Ultraviolet Cyber	Phoenix, AZ	501-1,000	517	258

Showing 25 of 3,288 defense cybersecurity companies based in the United States

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Defense cybersecurity companies based in the United States at a glance

As of Aug 28, 2026

11-50Median size (employees)

WashingtonLargest hub · 91 HQs

108,177Contacts with mobile numbers

69Emails re-verified in last 30 days

Companies by employee count

1-10

1,602

11-50

1,070

51-200

404

201-500

108

501-1,000

1,001-5,000

10001+

Defense cybersecurity companies by metro

Metro	Companies
Defense cybersecurity companies in Washington	91
Defense cybersecurity companies in New York	84
Defense cybersecurity companies in Houston	58
Defense cybersecurity companies in Austin	57
Defense cybersecurity companies in Columbia	56
Defense cybersecurity companies in Arlington	56
Defense cybersecurity companies in Miami	54

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “defense cybersecurity companies”, with match quality audited by blind human judging, and headquartered in the United States.
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: Contact records re-verify on a rolling cadence; 69 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many defense cybersecurity companies are there based in the United States?

There are 3,288 defense cybersecurity companies headquartered in the United States as of August 2026 (RevenueBase).

What is the largest company on this list?

Northrop Grumman, headquartered in San Diego, tops this list with the largest team on record.

Which city has the most defense cybersecurity companies?

Washington leads with 91 headquartered companies, followed by New York (84) and Houston (58).

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 31,764 verified decision-maker contacts tracked across these 3,288 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

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Defense cybersecurity companies by geography

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About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.