Company lists · Data refreshed September 2026
Top 13 Private security firms based in San Francisco, United States
RevenueBase identified 25 private security firms headquartered in San Francisco, United States as of September 2026 and tracks 659 professional contacts across them, including 79 with verified work emails. Across the United States, New York is the largest hub for this category (148 companies); San Francisco has 25.
This list covers private security firms headquartered in San Francisco, 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 14, 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.
The 13 largest private security firms based in San Francisco, United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 218 contacts → | ||||
Partial evidence “At ProGuard Security Services, we are unwavering in our commitment to achieving 100% accuracy through operational execution.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 2 | 65 contacts → | ||||
Partial evidence “STEELE Corporate Security Services is a global risk management firm that provides executive security, workplace stability, incident management, 24/ crisis response & GPS…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 3 | 34 contacts → | ||||
Indirect evidence “Global Secure 3 (GS3) is an international firm that provides risk management and investigation services to corporate and public sector organizations.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 4 | 32 contacts → | ||||
Indirect evidence “Everyone deserves to feel safe.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 5 | 27 contacts → | ||||
Partial evidence “Treeline Security combines the personal touch of a small, client-focused team, with the extensive reach and resources of a large network.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 6 | 12 contacts → | ||||
Strong evidence “Shield Corps Security is a private security firm dedicated to hiring military veterans.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 7 | 12 contacts → | ||||
Partial evidence “Our founder came to the USA as a mathematics student, and began his career as a security guard to support his education.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 8 | 9 contacts → | ||||
Partial evidence “The fundamental goal of CSS is to be an outstanding security organization dedicated to serving the Clients of CSS and the Public’s Safety, through its Officers, with effectiveness…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 9 | 3 contacts → | ||||
Partial evidence “1 Cerberus Security & Patrol is a licensed company founded on the principles of professionalism and excellence of service!” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 10 | 3 contacts → | ||||
Partial evidence “SOTR Solutions is a one-stop security consultancy offering "Security as a Strategy" and “Security as a Service.” We provide end-to-end guidance to create and run a security…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 11 | 2 contacts → | ||||
Strong evidence “Specializes in providing private security services for businesses, high end residences, government agencies, commercial complexes, home owner management services, & other public &…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 12 | 2 contacts → | ||||
Strong evidence “Leveraging decades of experience in public and private sector security management, Pacific Resilience Group delivers industry-leading expertise in insider risk, workplace violence…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 13 | 1 contacts → | ||||
Partial evidence “Asymmetric is a security advisory firm headquartered in San Francisco, serving clients nationwide.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
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: private security firms. 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 private security firms.
- Partial evidence
- Its own public description names part of private security firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name private security firms. 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 13 of 25 private security firms based in San Francisco, United States
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Private security firms based in San Francisco, United States at a glance
As of Sep 14, 2026Companies by employee count
Email recency for this list is measured across the whole United States list rather than for San Francisco, so it is reported there. Company counts and contact totals on this page are exact for San Francisco, over 25 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 private security firms, 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 San Francisco, United States whose own description of what they do matches “private security firms”. 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 private security firms), 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 private security firms, and records with no verified work email. Companies headquartered outside San Francisco 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 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 14, 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.
Private security firms by metro in the United States
- Private security firms in New York148
- Private security firms in Los Angeles133
- Private security firms in Houston102
- Private security firms in Miami82
- Private security firms in Chicago62
- Private security firms in Atlanta60
- Private security firms in Dallas59
- Private security firms in Austin49
- Private security firms in Phoenix44
- Private security firms in Las Vegas43
- Private security firms in Denver33
- Private security firms in Washington33
- Private security firms in San Diego28
- Private security firms in Charlotte27
- Private security firms in San Antonio25
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 private security firms, 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 private security firms are there based in San Francisco, United States?
RevenueBase identified 25 private security firms headquartered in San Francisco, 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?
Proguard Security Services, headquartered in San Francisco, tops this list with the largest team on record.
Which city in the United States has the most private security firms?
New York leads the United States with 148 headquartered companies, followed by Los Angeles (133) and Houston (102). San Francisco has 25.
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 verified decision-maker contacts tracked across these 25 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 14, 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.
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