Company lists · Data refreshed September 2026

Top 25 Operational technology security companies based in the United States

Name: Operational technology security companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 5, 2026 368 companies tracked

RevenueBase identified 368 operational technology security companies headquartered in the United States as of September 2026 and tracks 6,264 professional contacts across them, including 2,570 with verified work emails and 2,231 with mobile numbers. Houston is the largest hub.

This list covers operational technology security 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 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.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review

368Companies

6,264Contacts tracked

2,570Verified emails

2,231Mobile numbers

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The 25 largest operational technology security companies based in the United States

Ranked by team size

Top 25 of 368 operational technology security companies based in the United States, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names operational technology security companies: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#	Company	Headquarters	Employees	Contacts
1	PASIndirect evidence	Houston, TX, United StatesHQ checked Sep 5, 2026	201-500	1,231
	“PAS, part of Hexagon's Asset Lifecycle Intelligence division, delivers software solutions that prevent, detect, & remediate cyber threats, reduce process safety risks, and…” Source: company website · checked Sep 5, 2026
2	Dragos, INCPartial evidence	Hanover, MD, United StatesHQ checked Sep 5, 2026	501-1,000	551
	“Dragos provides the most effective OT cybersecurity technology for industrial and critical infrastructure to deliver on our global mission: to safeguard civilization.” Source: company website · checked Sep 5, 2026
3	DeepseasIndirect evidence	Globally Distributed, United StatesHQ checked Sep 5, 2026	201-500	182
	“With 30 years of experience in cyber defense, DeepSeas is trusted by nearly clients around the world, including Fortune 100 enterprises and mid-market organizations, municipality…” Source: company website · checked Sep 5, 2026
4	RMC GlobalIndirect evidence	Arlington, VA, United StatesHQ checked Sep 5, 2026	51-200	167
	“We believe resilience depends on minimizing and managing the increasing risks facing the critical infrastructure and industrial systems that support our country, companies, and…” Source: company website · checked Sep 5, 2026
5	NuharborIndirect evidence	Colchester, VT, United StatesHQ checked Sep 5, 2026	51-200	151
	“nuHarbor is a U.S-based cybersecurity firm trusted by public sector and critical infrastructure organizations nationwide.” Source: company website · checked Sep 5, 2026
6	OSC EdgeIndirect evidence	Atlanta, GA, United StatesHQ checked Sep 5, 2026	51-200	150
	“From CND in the Cloud to CSfC with Enterprise Remote Capabilities, OSC Edge empowers organizations with solutions that prepare them for today and tomorrow.” Source: company website · checked Sep 5, 2026
7	Shift5Indirect evidence	Arlington, VA, United StatesHQ checked Sep 5, 2026	51-200	129
	“Former military officers who stood up U.S.” Source: company website · checked Sep 5, 2026
8	Industrial Networking Solutions INSIndirect evidence	Richardson, TX, United StatesHQ checked Sep 5, 2026	51-200	116
	“INS provides industry-leading products, technical support and OT services for wired and wireless machine networking applications.” Source: company website · checked Sep 5, 2026
9	FoxguardPartial evidence	Christiansburg, VA, United StatesHQ checked Sep 5, 2026	51-200	116
	“Foxguard delivers comprehensive OT Cyber Security and Compute Solutions tailored to meet the unique needs of critical infrastructures.” Source: company website · checked Sep 5, 2026
10	DirectdefensePartial evidence	Denver, CO, United StatesHQ checked Sep 5, 2026	51-200	111
	“DirectDefense provides enterprise risk assessments, penetration testing, ICS/SCADA security services, and 24/7 managed security services for companies of all sizes.” Source: company website · checked Sep 5, 2026
11	Acet SolutionsIndirect evidence	Houston, TX, United StatesHQ checked Sep 5, 2026	201-500	106
	“ACET SOLUTIONS is a global OT Cybersecurity and Digital Transformation company serving the critical infrastructure industries.” Source: company website · checked Sep 5, 2026
12	Defy SecurityPartial evidence	Canonsburg, PA, United StatesHQ checked Sep 5, 2026	51-200	89
	“Defy Security was founded in 2017 with one primary goal: to change the cybersecurity buying experience by delivering value and service that is unmatched.” Source: company website · checked Sep 5, 2026
13	Integrated ITStrong evidence	Milford, MA, United StatesHQ checked Sep 5, 2026	51-200	87
	“Integrated IT delivers a seamless blend of IT operations and cybersecurity, designed to simplify complexity, strengthen security, and improve operational resilience.” Source: company website · checked Sep 5, 2026
14	DispelStrong evidence	Austin, TX, United StatesHQ checked Sep 5, 2026	51-200	86
	“Dispel delivers security that makes industrial operations run faster.” Source: company website · checked Sep 5, 2026
15	Verve By Rockwell AutomationIndirect evidence	Chicago, MO, United StatesHQ checked Sep 5, 2026	51-200	69
	“Verve Industrial Protection has ensured reliable and secure industrial control systems for 30 years.” Source: company website · checked Sep 5, 2026
16	RevelsiIndirect evidence	New York, NY, United StatesHQ checked Sep 5, 2026	51-200	65
	“RevelSI is a global cybersecurity, AI, software, and infrastructure services organization.” Source: company website · checked Sep 5, 2026
17	Apollo Information SystemsIndirect evidence	Dallas, TX, United StatesHQ checked Sep 5, 2026	51-200	64
	“Apollo Information Systems delivers intelligence-led cybersecurity solutions for government agencies, educational institutions, and enterprises.” Source: company website · checked Sep 5, 2026
18	Cyber Defense TechnologiesPartial evidence	Dulles, VA, United StatesHQ checked Sep 5, 2026	11-50	61
	“We specialize in providing comprehensive cyber security solutions by leveraging our information security background in the GovCon and military experiences to serve the federal…” Source: company website · checked Sep 5, 2026
19	Cyberforce QIndirect evidence	Plymouth, MI, United StatesHQ checked Sep 5, 2026	11-50	56
	“CyberForce\|Q has provided proven cybersecurity program advancements for over 30 years.” Source: company website · checked Sep 5, 2026
20	Phosphorus Cybersecurity INCPartial evidence	Nashville, TN, United StatesHQ checked Sep 5, 2026	51-200	53
	“Phosphorus, a Dragos company, is the leading xIoT security and management platform that proactively manages the expanding IoT, OT, and IoMT attack surface.” Source: company website · checked Sep 5, 2026
21	RED GroupStrong evidence	Metairie, LA, United StatesHQ checked Sep 5, 2026	51-200	52
	“RED Group provides end-to-end Operational Technology & Industrial Control Systems (OT/ICS) solutioning and delivery expertise, from conceptual consulting, through detailed…” Source: company website · checked Sep 5, 2026
22	Secure TracesPartial evidence	Alpharetta, GA, United StatesHQ checked Sep 5, 2026	51-200	52
	“Secure Traces is a unique cyber security services provider with an impeccable track record of delivering outstanding services, we are driven by passion and backed by our extensive…” Source: company website · checked Sep 5, 2026
23	Industrial DefenderIndirect evidence	Foxborough, MA, United StatesHQ checked Sep 5, 2026	51-200	51
	“Industrial Defender protects the world’s critical infrastructure from cyberattacks.” Source: company website · checked Sep 5, 2026
24	CSE Icon, INCStrong evidence	The Woodlands, TX, United StatesHQ checked Sep 5, 2026	51-200	50
	“CSE ICON is a technology and integration services organization focused on the design, development and implementation of Operations Technologies and Information Systems.” Source: company website · checked Sep 5, 2026
25	Clearfocus TechnologiesPartial evidence	Leesburg, VA, United StatesHQ checked Sep 5, 2026	51-200	43
	“ClearFocus® Technologies provides advanced cybersecurity services that secure our nation’s most sensitive assets.” Source: company website · checked Sep 5, 2026

Showing 25 of 368 operational technology security companies based in the United States

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Operational technology security companies based in the United States at a glance

As of Sep 5, 2026

11-50Median size (employees)

HoustonLargest hub · 19 HQs

2,231Contacts with mobile numbers

Sep 5, 2026Data refreshed

Companies by employee count

1-10

179

11-50

136

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

Verified emails by last verification

0–30

2,397

31–60

162

61–90

90–180

180+

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 operational technology security 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 “operational technology security 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 operational technology security 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, 2,570 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.

Frequently asked

How many operational technology security companies are there based in the United States?

RevenueBase identified 368 operational technology security 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?

PAS, headquartered in Houston, tops this list with the largest team on record.

Which city has the most operational technology security companies?

Houston leads with 19 headquartered companies, followed by New York (12) and Atlanta (8).

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 2,570 verified decision-maker contacts tracked across these 368 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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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.