Company lists · Data refreshed September 2026
Top 25 Security services companies based in the United States
RevenueBase identified 4,727 security services companies headquartered in the United States as of September 2026 and tracks 241,198 professional contacts across them, including 23,859 with verified work emails and 74,794 with mobile numbers. New York is the largest hub.
This list covers security services 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. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 6, 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 security services companies 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 6, 2026Thanks. The Data Team will review it. | |||||
| 2 | 38,634 | ||||
“Securitas knows Security.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 3 | UnemployedStrong evidence | 4,038 | |||
“Excelsior Defense is a security and investigations company based out of St.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 4 | 3,612 | ||||
“EVERYWHERE SECURITY MATTERS.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 5 | 3,592 | ||||
“U.S.” Source: company website · checked Sep 6, 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 6, 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 6, 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 6, 2026Thanks. The Data Team will review it. | |||||
| 9 | 2,045 | ||||
“Everon is a leading national provider of commercial security, video, fire, sprinkler, and life safety solutions for complex, multi-site businesses and organizations.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 10 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 12 | 1,727 | ||||
“HSS is now Tarian!” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 13 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 14 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 15 | 1,399 | ||||
“Weiser Security Services is the 11th largest security service provider in the U.S.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 16 | 1,375 | ||||
“Guardsmark, LLC provides security services.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 17 | 1,297 | ||||
“More than a provider, we’re an active partner.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 18 | 1,190 | ||||
“DSI Security Services offers armed and unarmed uniformed security guard services.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 19 | 1,151 | ||||
“SOS Security is a known innovator and leader in the security and protective services industry.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 20 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 21 | 1,120 | ||||
“Per Mar Security Services is the largest full-service security solutions provider in the Midwest.” Source: company website · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 22 | 1,118 | ||||
“Securitas Critical Infrastructure Services, Inc.(SCIS) is a provider of specialized security and fire services to the highly regulated Nuclear, Aerospace, Defense, Energy, and…” Source: company website · checked Sep 6, 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 6, 2026Thanks. The Data Team will review it. | |||||
| 24 | 1,062 | ||||
“Founded in 1982, St.” Source: company website · checked Sep 6, 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 6, 2026Thanks. The Data Team will review it. | |||||
Showing 25 of 4,727 security services companies based in the United States
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Security services companies based in the United States at a glance
As of Sep 6, 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 security services companies, 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 “security services companies”. 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 security services companies, 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, 23,859 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 6, 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.
Security services companies by metro
- Security services companies in New York136
- Security services companies in Los Angeles128
- Security services companies in Houston116
- Security services companies in Miami92
- Security services companies in Dallas66
- Security services companies in Atlanta60
- Security services companies in Chicago58
- Security services companies in Austin48
- Security services companies in Phoenix47
- Security services companies in Denver38
- Security services companies in Las Vegas37
- Security services companies in Orlando33
- Security services companies in Tampa33
- Security services companies in San Antonio31
- Security services companies in Charlotte30
- Security services companies in Baltimore29
- Security services companies in San Diego27
- Security services companies in San Jose25
Frequently asked
How many security services companies are there based in the United States?
RevenueBase identified 4,727 security services companies 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 security services companies?
New York leads with 136 headquartered companies, followed by Los Angeles (128) and Houston (116).
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 23,859 verified decision-maker contacts tracked across these 4,727 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 6, 2026.
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Security services companies by geography
- Security services companies based in the United Kingdom
- Security services companies based in Brazil
- Security services companies based in France
- Security services companies based in Germany
- Security services companies based in Canada
- Security services companies based in Italy
- Security services companies based in the Netherlands
- Security services companies based in Australia
- Security services companies based in South Africa
- Security services companies based in Mexico
- Security services companies based in Spain
- Security services companies 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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