Company lists · Data refreshed September 2026
Top 25 Private security firms based in the United States
RevenueBase identified 4,203 private security firms headquartered in the United States as of September 2026 and tracks 234,160 professional contacts across them, including 22,245 with verified work emails and 70,384 with mobile numbers. New York is the largest hub.
This list covers private security firms 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, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 25 largest private security firms based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 62,804 | ||||
“Allied Universal®, a leading security and facility services company, provides proactive security services and cutting-edge smart technology to deliver evolving, tailored solutions…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 2 | 38,634 | ||||
“Securitas knows Security.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 3 | UnemployedPartial evidence | 4,038 | |||
“Excelsior Defense is a security and investigations company based out of St.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 4 | 3,612 | ||||
“EVERYWHERE SECURITY MATTERS.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 5 | 3,592 | ||||
“U.S.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 6 | 2,500 | ||||
“The industry leader in security, Security Industry Specialists offers unique solutions to Fortune 500 companies, international events, and celebrity clients.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 7 | 2,266 | ||||
“Andy Frain Services.America's leading provider of integrated solutions to security and events needs for over 90 years.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 8 | 2,174 | ||||
“Through an ISO® 9001:2015 Certified Quality Management System (QMS), Walden Security has earned an award-winning reputation for business excellence and employee satisfaction…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 9 | 2,025 | ||||
“Crisis24, a GardaWorld company, is widely regarded as the leading integrated risk management, crisis response, consulting, and global protective solutions firm, serving the…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 10 | Pinkerton Comprehensive Risk ManagementPartial evidence | 2,022 | |||
“Pinkerton, established in 1850 by Allan Pinkerton, stands as a leading global provider of security and risk management solutions.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 11 | 1,949 | ||||
“Paragon Systems employs over 10,500 professionals in specialized operations providing security, fire, investigations, inspections, cybersecurity, risk management, and mission…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 12 | 1,781 | ||||
“Whelan’s commitment to quality and service has made us one of the foremost respected, successful and fastest growing companies in the industry.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 13 | 1,727 | ||||
“HSS is now Tarian!” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 14 | 1,639 | ||||
“Sunstates Security, LLC is one of the industry's leading providers of contract security services with a differentiated approach to providing successful, cost-effective, quality…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 15 | 1,441 | ||||
“Admiral Security Services provides professional armed and unarmed uniformed security officers, unparalleled site management and unwavering corporate support that exceeds client…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 16 | 1,399 | ||||
“Weiser Security Services is the 11th largest security service provider in the U.S.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 17 | 1,375 | ||||
“Guardsmark, LLC provides security services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 18 | 1,297 | ||||
“More than a provider, we’re an active partner.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 19 | 1,190 | ||||
“DSI Security Services offers armed and unarmed uniformed security guard services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 20 | 1,151 | ||||
“SOS Security is a known innovator and leader in the security and protective services industry.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 21 | 1,138 | ||||
“At Titan Security Group, we understand that each client is unique, with specific security needs shaped by the type of property and its location.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 22 | 1,120 | ||||
“Per Mar Security Services is the largest full-service security solutions provider in the Midwest.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 23 | 1,081 | ||||
“Twenty-five years ago Andrews International (AI) began forming a network of the world’s foremost security authorities and connecting with strategic partners for operations…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 24 | 1,062 | ||||
“Founded in 1982, St.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 25 | 1,050 | ||||
“Brosnan Risk Consultants, Ltd.(BRC) is a security risk management firm focusing on physical security, emergency security, disaster preparedness and recovery and management…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
Showing 25 of 4,203 private security firms based in the United States
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Private security firms based in the United States at a glance
As of Sep 5, 2026Companies by employee count
Verified emails by last verification
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 evidence 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 SmartSearch, 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 “private security firms”. Matching reads each company's description, not its industry code or its name.
- 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 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 an evidence 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, 22,245 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 5, 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
- 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 Orlando37
- Private security firms in Denver33
- Private security firms in Washington33
- Private security firms in Tampa31
- Private security firms in San Diego28
- Private security firms in Seattle28
- Private security firms in Charlotte27
- Private security firms in Nashville27
- Private security firms in San Antonio25
- Private security firms in San Francisco25
Frequently asked
How many private security firms are there based in the United States?
RevenueBase identified 4,203 private security firms 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?
Allied Universal, headquartered in Irvine, tops this list with the largest team on record.
Which city has the most private security firms?
New York leads with 148 headquartered companies, followed by Los Angeles (133) and Houston (102).
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 22,245 verified decision-maker contacts tracked across these 4,203 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 5, 2026.
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Private security firms by geography
- Private security firms based in the United Kingdom
- Private security firms based in France
- Private security firms based in Brazil
- Private security firms based in Germany
- Private security firms based in Canada
- Private security firms based in Italy
- Private security firms based in the Netherlands
- Private security firms based in Australia
- Private security firms based in South Africa
- Private security firms based in Mexico
- Private security firms based in Spain
- Private security firms based in Argentina
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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 SmartSearch, 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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