Company lists · Data refreshed September 2026
Top 25 Critical infrastructure defense based in Australia
RevenueBase identified 809 critical infrastructure defense headquartered in Australia as of September 2026 and tracks 11,062 professional contacts across them, including 3,599 with verified work emails. Sydney is the largest hub.
This list covers critical infrastructure defense headquartered in Australia, 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 16, 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 critical infrastructure defense based in Australia
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,813 contacts → | ||||
Indirect evidence “At Wilson Security, we are committed to building a safer future for everyone.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 2 | 510 contacts → | ||||
Indirect evidence “Founded in 1923, SNP is one of Australia’s leading security services providers with over 2,500 employees nationwide.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 3 | 352 contacts → | ||||
Indirect evidence “We are an Australian-owned, full-service ICT Solutions and Cyber Security provider with a locally based team of over 450 passionate Aussies.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 4 | 274 contacts → | ||||
Indirect evidence “MA Services Group is a 100% Australian owned company, founded with the vision of providing high performance, customer centric services in a safe and fair environment.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 5 | 228 contacts → | ||||
Indirect evidence “We know how to offer the most effective security to our customers.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 6 | 198 contacts → | ||||
Indirect evidence “ACES Group, an Australian owned security organisation delivers security, risk and safety management, event management and training services to multiple industries including…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 7 | 178 contacts → | ||||
Indirect evidence “For more than 130 years, we have stood alongside our community, protecting homes, families, businesses, and communities.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 8 | 170 contacts → | ||||
Indirect evidence “Ensuring your business is handling cyber security risks effectively has never been more important.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 9 | 123 contacts → | ||||
Indirect evidence “Triskele Labs is one of Australia’s fastest growing cybersecurity companies.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 10 | 115 contacts → | ||||
Indirect evidence “Innovative Managed Services: Bridging Assets, Systems, and Security Welcome to Renew IT, your trusted partner in delivering comprehensive managed services, systems integration…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 11 | 111 contacts → | ||||
Indirect evidence “New Era delivers Technology Solutions that securely connect people, places, and information in a rapidly changing digital world.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 12 | 104 contacts → | ||||
Indirect evidence “Sekuro is a cyber security and digital resiliency solutions provider that helps CIOs and CISOs take a strategic approach to cyber security risk mitigation and building business…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 13 | 101 contacts → | ||||
Indirect evidence “ARA Security delivers turnkey security solutions to a number of industries across Australia.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 14 | 93 contacts → | ||||
Indirect evidence “Australia’s cyber-first Managed Service Provider and true technology partner.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 15 | 87 contacts → | ||||
Indirect evidence “Established in 2001, ISEC is a leading provider of protective security, safety, risk management, and training services to the corporate, commercial and government sectors.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 16 | 82 contacts → | ||||
Indirect evidence “National Protective Services is a leading professional security company, specialising in the provision of quality and tailored protective services and products to ensure optimum…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 17 | 74 contacts → | ||||
Indirect evidence “AG Security Group is South Australia's leading and largest locally owned security organisation that has been protecting Australians for more than 35 years.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 18 | 71 contacts → | ||||
Indirect evidence “ABOUT US Nexar Group foundations are built on driving change and evolution to not only the security industry, but for all of our services.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 19 | 70 contacts → | ||||
Indirect evidence “Northbridge is an Australian-owned cybersecurity services provider with more than 25 years’ experience delivering engineered, integrated and fully managed security services to…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 20 | 63 contacts → | ||||
Indirect evidence “Established in 2006, Sturdie has grown to become one of the most respected providers of high-quality electrical services and security technology in Australia and New Zealand.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 21 | 61 contacts → | ||||
Indirect evidence “Discover 3Columns, your premier destination for cutting-edge cyber security solutions.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 22 | 59 contacts → | ||||
Indirect evidence “Guarding Solutions | Armed Guards | 24/7 Grade A1 Monitoring | Mobile Patrols | Electronics | Advisory EXEC Security is an Australian owned, national company that specialises in…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 23 | 57 contacts → | ||||
Indirect evidence “IPSec are specialists in information asset and cyber protection; security experts who know how to mitigate cyber risk by assisting in the protection of valuable intelligence…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 24 | 55 contacts → | ||||
Indirect evidence “Australian owned Advent Security has been a leader in providing exceptional, value-for-money services to local, national and international clients in the public, private and…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 25 | 53 contacts → | ||||
Indirect evidence “Guardian Venue Management International is a proudly Australian-owned company, dedicated to delivering the highest standards of Security Solutions, Customized Protection, Traffic…” Source: RevenueBase Database · checked Sep 16, 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: critical infrastructure defense. 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 critical infrastructure defense.
- Partial evidence
- Its own public description names part of critical infrastructure defense, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name critical infrastructure defense. 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 809 critical infrastructure defense based in Australia
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Critical infrastructure defense based in Australia at a glance
As of Sep 16, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for Australia, so it is reported there. Company counts and contact totals on this page are exact for Australia, over 809 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 critical infrastructure defense, 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 Australia whose own description of what they do matches “critical infrastructure defense”. 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 critical infrastructure defense), 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 critical infrastructure defense, and records with no verified work email. Companies headquartered outside Australia 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, 3,599 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 16, 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.
Critical infrastructure defense by metro
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 critical infrastructure defense, 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 critical infrastructure defense are there based in Australia?
RevenueBase identified 809 critical infrastructure defense headquartered in Australia 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?
Wilson Security, headquartered in Essendon Fields, tops this list with the largest team on record.
Which city has the most critical infrastructure defense?
Sydney leads with 140 headquartered companies, followed by Melbourne (129) and Brisbane (54).
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 3,599 verified decision-maker contacts tracked across these 809 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 16, 2026.
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Critical infrastructure defense by geography
- Critical infrastructure defense based in Adelaide, Australia
- Critical infrastructure defense based in Brisbane, Australia
- Critical infrastructure defense based in Canberra, Australia
- Critical infrastructure defense based in Melbourne, Australia
- Critical infrastructure defense based in Perth, Australia
- Critical infrastructure defense based in Sydney, Australia
- Critical infrastructure defense based in Belo Horizonte, Brazil
- Critical infrastructure defense based in Brasilia, Brazil
- Critical infrastructure defense based in Curitiba, Brazil
- Critical infrastructure defense based in Porto Alegre, Brazil
- Critical infrastructure defense based in Rio De Janeiro, Brazil
- Critical infrastructure defense based in Sao Paulo, Brazil
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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.
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