Company lists · Data refreshed September 2026
Top 11 Security firms based in Boston, United States
RevenueBase identified 25 security firms headquartered in Boston, United States as of September 2026 and tracks 522 professional contacts across them, including 53 with verified work emails. New York is the largest hub.
This list covers security firms headquartered in Boston, 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 11 largest security firms based in Boston, United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 91 contacts → | ||||
Strong evidence “Windwalker is an award-winning small business with over 25 years of experience delivering cutting-edge security, IT, and training solutions.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 2 | 63 contacts → | ||||
Strong evidence “Longwood Security Services delivers ‘in-house style security services, with contract muscle,’ to Boston area colleges and universities, hospitals and residential communities.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 3 | 34 contacts → | ||||
Strong evidence “New England Security is a full-service security company with the professional experience and resources to provide superior protection and to maximize your infrastructure…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 4 | 21 contacts → | ||||
Strong evidence “MCH Security and Protective Services, LLC is a fully insured, bonded Security Company licensed by the Mass State Police CERT Unit.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 5 | 8 contacts → | ||||
Strong evidence “At Nationwide Security Service we are your single source security solution.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 6 | 8 contacts → | ||||
Strong evidence “CapitalTN is a cutting-edge security company committed to redefining safety and peace of mind.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 7 | 8 contacts → | ||||
Strong evidence “Headquartered in Boston MA, Redcon Security aims to become the new industry standard for Security Guard Services.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 8 | 6 contacts → | ||||
Strong evidence “Physical security consulting firm providing assessments (risk and existing conditions), security road mapping, security system design, project management, commissioning, and…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 9 | 5 contacts → | ||||
Strong evidence “ECM Security Inc.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 10 | 2 contacts → | ||||
Strong evidence “The founders and team at Matthews & Matthews, LLC provides trusted and confidential investigative, executive security, and management consulting expertise to Companies and…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 11 | 2 contacts → | ||||
Strong evidence “At Apparition, LLC, we are more than just a security company - we are a team of professionals who share a deep commitment to protecting our clients' safety and security.” 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: 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 security firms.
- Partial evidence
- Its own public description names part of security firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name 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 11 of 25 security firms based in Boston, United States
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Security firms based in Boston, 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 Boston, so it is reported there. Company counts and contact totals on this page are exact for Boston, 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 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 Boston, United States whose own description of what they do matches “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 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 security firms, and records with no verified work email. Companies headquartered outside Boston 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, 53 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.
Security firms by metro in the United States
- Security firms in New York190
- Security firms in Los Angeles168
- Security firms in Houston156
- Security firms in Miami125
- Security firms in Dallas85
- Security firms in Atlanta83
- Security firms in Chicago77
- Security firms in Phoenix71
- Security firms in Austin67
- Security firms in Las Vegas58
- Security firms in Charlotte49
- Security firms in Orlando49
- Security firms in Tampa47
- Security firms in Denver46
- Security firms in San Diego46
- Security firms in San Antonio42
- Security firms in San Francisco41
- Security firms in Baltimore35
- Security firms in Indianapolis34
- Security firms in Nashville34
- Security firms in Jacksonville33
- Security firms in San Jose33
- Security firms in Seattle33
- Security firms in Fort Lauderdale32
- Security firms in Sacramento32
- Security firms in Washington32
- Security firms in Philadelphia27
- Security firms in Portland26
- Security firms in Beverly Hills25
- Security firms in Boston25
- Security firms in Columbus25
- Security firms in Memphis25
- Security firms in Raleigh25
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 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 security firms are there based in Boston, United States?
RevenueBase identified 25 security firms headquartered in Boston, 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?
Windwalker Group, headquartered in Boston, tops this list with the largest team on record.
Which city has the most security firms?
New York leads with 190 headquartered companies, followed by Los Angeles (168) and Houston (156).
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 53 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.