Company lists · Data refreshed September 2026
Top 25 Cyber security firms based in Ireland
RevenueBase identified 72 cyber security firms headquartered in Ireland as of September 2026 and tracks 1,555 professional contacts across them, including 689 with verified work emails. Dublin is the largest hub.
This list covers cyber security firms headquartered in Ireland, 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 25 largest cyber security firms based in Ireland
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 288 contacts → | ||||
Strong evidence “Nostra was established in 2006 and in that time has become one of Ireland’s most trusted providers of Managed IT and Cyber Security Services for a wide range of sectors.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 2 | 189 contacts → | ||||
Partial evidence “At Smarttech247 we help global companies defend against cyber crime and protect their operations.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 3 | 81 contacts → | ||||
Indirect evidence “BH Consulting is an independent consulting firm in operation since 2004.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 4 | 77 contacts → | ||||
Indirect evidence “TitanHQ and Redstor have merged to launch CyberSentriq, a cybersecurity champion built for MSPs and their customers.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 5 | 75 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 6 | 65 contacts → | ||||
Partial evidence “Secureism is founded by the brains who were awarded for their contribution to secure the cyber space on national as well as international level.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 7 | 36 contacts → | ||||
Strong evidence “We are a pure play IT security company, which allows us to focus solely on protecting your business from cyber threats.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 8 | 27 contacts → | ||||
Partial evidence “Paradyn is a leading provider of IT security and consultancy services in Ireland, offering a comprehensive, best-in-class suite of security services to monitor, protect and defend…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 9 | 21 contacts → | ||||
Strong evidence “CommSec is an Irish cyber security company helping organisations protect their systems, data, and operations against modern cyber threats.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 10 | 20 contacts → | ||||
Strong evidence “Dectar is an innovative European cyber security firm focused on proactively preventing cyberattacks and protecting the critical data at the core of every organization.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 11 | 15 contacts → | ||||
Strong evidence “We Simplify Cyber Security.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 12 | 15 contacts → | ||||
Indirect evidence “Exclusive Networks is a global trusted cybersecurity specialist for digital infrastructure helping to drive the transition to a totally trusted digital future for all people and…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 13 | 13 contacts → | ||||
Partial evidence “Atoro is a cyber compliance consultancy for scaling software companies, and Europe's first ISO 42001 certified consultancy.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 14 | 12 contacts → | ||||
Partial evidence “Our aim is to help organizations defend against cyber-attacks by finding their vulnerabilities in a proactive manner.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 15 | 11 contacts → | ||||
Partial evidence “Ward Solutions is Ireland’s largest Information Security provider.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 16 | 10 contacts → | ||||
Strong evidence “Enterprise Defence are an award winning team of cyber security specialists.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 17 | 8 contacts → | ||||
Indirect evidence “Intercept Technologies, the game-changer in advanced monitoring and state-of-the-art tooling, offering unparalleled identification and remediation of potential exposures and…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 18 | 7 contacts → | ||||
Indirect evidence “Secora Consulting are experts in cybersecurity and risk mitigation.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 19 | 7 contacts → | ||||
Indirect evidence “At Cyberhealth, we specialise in providing cost-effective cybersecurity services tailored specifically for small to medium-sized businesses (SMBs).” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 20 | 7 contacts → | ||||
Partial evidence “Leacam offers security-first IT support services that help protect your business, minimise the number and severity of security incidents, and reduces your overall IT costs.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 21 | 5 contacts → | ||||
Indirect evidence “Netfocus IT Solutions provides a comprehensive range of managed IT and cybersecurity services, supporting businesses in maintaining system uptime, safeguarding data, and enhancing…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 22 | 5 contacts → | ||||
Partial evidence “At ITUS we believe that effective cybersecurity begins with understanding cyber risk for your business.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 23 | 5 contacts → | ||||
Partial evidence “Novi delivers security-oriented IT services that reduce risk and enable growth.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 24 | 4 contacts → | ||||
Partial evidence “IT Security People Ltd was set up in response to the surge in Cybercrime exploits and IT Security threats in the Irish market.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 25 | 4 contacts → | ||||
Indirect evidence “Attackers already know what's in your environment.” 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: cyber 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 cyber security firms.
- Partial evidence
- Its own public description names part of cyber security firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name cyber 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 25 of 72 cyber security firms based in Ireland
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 689 reachable decision-makers.
Free signup · no credit card
Cyber security firms based in Ireland at a glance
As of Sep 14, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for Ireland, so it is reported there. Company counts and contact totals on this page are exact for Ireland, over 72 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 cyber 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 Ireland whose own description of what they do matches “cyber 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 cyber 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 cyber security firms, and records with no verified work email. Companies headquartered outside Ireland 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, 689 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.
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 cyber 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 cyber security firms are there based in Ireland?
RevenueBase identified 72 cyber security firms headquartered in Ireland 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?
Nostra, headquartered in Dublin, tops this list with the largest team on record.
Which city has the most cyber security firms?
Dublin leads with 23 headquartered companies, followed by Belfast (2) and Cork (2).
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 689 verified decision-maker contacts tracked across these 72 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.
Ready to reach these companies? Verified emails and direct dials for all 72 cyber security firms based in Ireland. Start with a free account, no credit card.
Download this list →Related lists
Cyber security firms by geography
- Cyber security firms based in Brisbane, Australia
- Cyber security firms based in Canberra, Australia
- Cyber security firms based in Melbourne, Australia
- Cyber security firms based in Sydney, Australia
- Cyber security firms based in Belo Horizonte, Brazil
- Cyber security firms based in Rio De Janeiro, Brazil
- Cyber security firms based in Sao Paulo, Brazil
- Cyber security firms based in Calgary, Canada
- Cyber security firms based in Montreal, Canada
- Cyber security firms based in Ottawa, Canada
- Cyber security firms based in Toronto, Canada
- Cyber security firms based in Vancouver, Canada
Browse the directory
Browse: Companies home · All Ireland lists · All Cyber security firms lists · New lists
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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Cyber security firms based in Brisbane, Australia
- Cyber security firms based in Canberra, Australia
- Cyber security firms based in Melbourne, Australia
- Cyber security firms based in Sydney, Australia
- Cyber security firms based in Belo Horizonte, Brazil
- Cyber security firms based in Rio De Janeiro, Brazil