Top Cybersecurity Companies in California
We ranked 6 cybersecurity companies in California on client reviews, how many are verified, service focus and profile completeness. Updated October 2026. How rankings work
Firms that assess, harden and monitor systems, and help companies meet security and compliance requirements.
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Offensive security firm headquartered in Tempe, Arizona, providing penetration testing, red teaming and continuous security testing for enterprises.
No reviews yet
San Francisco, CA
- Cybersecurity
Managed detection and response across an organization's existing security environment.
No reviews yet
Palo Alto, CA
- Cybersecurity
IT support and compliance consultancy serving Alaska, the San Francisco Bay Area, and Washington.
No reviews yet
Walnut Creek, CA
- Managed IT Services
- Cybersecurity
Medical-device software, verification, and connected-product security.
No reviews yet
Irvine, CA
- Custom Software Development
- Software Testing & QA
- Cybersecurity
Test automation, modular QA engineering and game or connected-product testing.
No reviews yet
San Mateo, CA
- Software Testing & QA
- Cybersecurity
San Diego custom software developer building mobile, web, desktop and enterprise applications since 1990.
No reviews yet
San Diego, CA
- Custom Software Development
- Mobile App Development
- Web Development
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