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Series A Cybersecurity companies in London

Companies defending or attacking software, networks, and cloud infrastructure. Filtered to Series A-stage companies headquartered in London.

Built from a search like: “Top Series A Cybersecurity companies in London”

Ranked by current headcount across Series A Cybersecurity companies in London. Refreshed daily.

  1. 1
    Risk Ledger· London, England, United Kingdom
    • Series A
    • 85 employees
    • Founded 2018
  2. 2
    ThreatSpike· London, England, United Kingdom
    • Series A
    • 75 employees
    • Founded 2011
  3. 3
    Ubisecure· London, England, United Kingdom
    • Series A
    • 51 employees
    • Founded 2002
  4. 4
    Venari Security· London, England, United Kingdom
    • Series A
    • 45 employees
    • Founded 2021
  5. 5
    Maze· London, England, United Kingdom
    • Series A
    • 36 employees
    • Founded 2024
  6. 6
    ThreatAware· London, England, United Kingdom
    • Series A
    • 34 employees
    • Founded 2019
  7. 7
    Cydome· London, England, United Kingdom
    • Series A
    • 32 employees
    • Founded 2019
  8. 8
    Equixly API Security· London, England, United Kingdom
    • Series A
    • 31 employees
    • Founded 2022
  9. 9
    Cybertonica Ltd· London, England, United Kingdom
    • Series A
    • 11 employees
    • Founded 2015

Find engineers at Series A Cybersecurity companies in London

Searching for “engineers at top Series A Cybersecurity companies in London” surfaces this slice of the market. The list above ranks Cybersecurity companies headquartered in London whose latest disclosed round is Series A, by current headcount, drawn from public LinkedIn and Crunchbase records. With 9 matching companies in our index, this is a tight read on where the Cybersecurity talent in London is heating up.

Three filters at once narrows the field hard. The companies that survive all three — Series A, Cybersecurity, in London — are usually the most targeted recruiting pool a hiring manager can ask for. Senior engineers, founding designers, and product leads here are about to become Cybersecurity’s next operators and angel investors.

Refolk converts this list into a live search. Ask for “senior engineers at Series A Cybersecurity companies in London hiring” or “founders of Series A Cybersecurity companies in London who left in the last year” and Refolk returns a ranked shortlist with the evidence behind each match.

How this list is built

Refolk pulled Cybersecurity companies headquartered in London whose latest disclosed funding round is Series A from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 3 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 07:21:50 GMT

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