Company lists · Data verified August 2026
Top 25 Cybersecurity companies in the United States
Our directory lists 8,870 cybersecurity companies in the United States, with 375,857 professional contacts and 129,210 email addresses. The list was last updated in August 2026, and New York is the single most-represented city among the companies listed.
Cybersecurity companies provide products and services that protect systems, networks, applications, devices, and data from unauthorized access, disruption, or misuse. This list covers companies that provide cybersecurity products, services, consulting, assessments, monitoring, incident response, or related protection for digital systems and data. Ranked by employee count, largest first. Data current as of August 28, 2026.
The 25 largest cybersecurity companies in the United States
Ranked by employees| # | Company | Verified emails |
|---|---|---|
| 1 |  CISCO | 25,769 |
| 2 |  Symantec | 876 |
| 3 |  Imperva | 829 |
| 4 |  Mandiant Part Of Google Cloud | 509 |
| 5 |  HP Wolf Security | 30 |
| 6 | Subject Matter Expert | 2 |
| 7 | Fusionx Advanced Adversary Team | 2 |
| 8 |  Sonitrol | 2 |
| 9 |  Vmware Vdefend | 1 |
| 10 |  Distilled Media INC | 0 |
| 11 |  Plum Cyber | 0 |
| 12 |  Data Tactics | 0 |
| 13 |  Maxhed LLC | 0 |
| 14 |  MRX Technologies USA | 0 |
| 15 |  Iron Mountain Iron Cloud | 0 |
| 16 | Chronicle | 0 |
| 17 |  Krypteia Group | 0 |
| 18 | Cyber Security Professionals In USA | 0 |
| 19 |  Rubrik | 2,545 |
| 20 |  Commvault | 2,207 |
| 21 |  Qualys | 2,121 |
| 22 |  Netskope | 1,996 |
| 23 |  Varonis | 1,673 |
| 24 |  Trellix | 1,633 |
| 25 |  Infoblox | 1,604 |
| 26 |  Knowbe4 | 1,484 |
| 27 |  Barracuda | 1,463 |
| 28 |  OPTIV | 1,422 |
Showing 25 of 8,870 cybersecurity companies in the United States
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Cybersecurity companies in the United States at a glance
As of Aug 28, 2026Companies by employee count
Companies by metro
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 “cybersecurity companies”, with match quality audited by blind human judging, and headquartered in the United States.
- Ranking
- Employee count, largest first. Ranges reflect verified bands, not estimates.
- Verification
- Contact records re-verify on a rolling cadence; 1273 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 cybersecurity companies are in the directory?
The directory lists 8,870 cybersecurity companies in the United States.
Which city has the most cybersecurity companies?
New York is the single most-represented city among the cybersecurity companies on the list.
How many contacts are available for cybersecurity companies?
The directory includes 375,857 professional contacts and 129,210 email addresses for the listed cybersecurity companies.
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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.