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Top AI companies in London

Companies building AI products, foundation models, and applied ML platforms. Filtered to companies headquartered in London.

Built from a search like: “Top AI companies in London”

Ranked by current headcount across AI companies headquartered in London. Refreshed daily.

  1. 1
    UCL· London, England, United Kingdom
    • Grant
    • 24.3k employees
  2. 2
    King's College London· London, England, United Kingdom
    • Grant
    • 20.5k employees
  3. 3
    Imperial College London· London, England, United Kingdom
    • Grant
    • 17.8k employees
    • Founded 1907
  4. 4
    Google DeepMind· London, England, United Kingdom
    • Series A
    • 8.3k employees
    • Founded 2010
  5. 5
    LGC· London, England, United Kingdom
    • 2.3k employees
    • Founded 1996
  6. 6
    The Francis Crick Institute· London, England, United Kingdom
    • Convertible note
    • 1.9k employees
    • Founded 2011
  7. 7
    National Physical Laboratory (NPL)· Teddington, England, United Kingdom
    • 1.8k employees
  8. 8
    The Institute of Cancer Research· London, England, United Kingdom
    • Grant
    • 1.6k employees
    • Founded 1909
  9. 9
    Royal Botanic Gardens, Kew· Richmond Upon Thames, England, United Kingdom
    • 1.4k employees
  10. 10
    Perceptive Inc.· London, England, United Kingdom
    • Private equity
    • 1.2k employees
    • Founded 1996
  11. 11
    Chatham House· London, England, United Kingdom
    • 1.1k employees
    • Founded 1920
  12. 12
    Institute of Physics· London, England, United Kingdom
    • 869 employees
  13. 13
    National Centre for Social Research· London, England, United Kingdom
    • 777 employees
    • Founded 1969
  14. 14
    ElevenLabs· London, England, United Kingdom
    • Series D
    • 752 employees
    • Founded 2022
  15. 15
    Cochrane· London, England, United Kingdom
    • 696 employees
    • Founded 1993
  16. 16
    Institute of Psychiatry, Psychology & Neuroscience· London, England, United Kingdom
    • 675 employees
  17. 17
    The Alan Turing Institute· London Colney, England, United Kingdom
    • Grant
    • 598 employees
    • Founded 2015
  18. 18
    Omdia· London, England, United Kingdom
    • 573 employees
    • Founded 2020
  19. 19
    Genomics England· London, England, United Kingdom
    • 561 employees
    • Founded 2013
  20. 20
    ODI Global· London, England, United Kingdom
    • 561 employees
    • Founded 1960
  21. 21
    Veramed· Twickenham, England, United Kingdom
    • 556 employees
    • Founded 2012
  22. 22
    Berlin Institute of Technology (Technische Universität Berlin)· London, England, United Kingdom
    • 492 employees
  23. 23
    Legal 500· London, England, United Kingdom
    • 418 employees
    • Founded 1987
  24. 24
    IB· London Colney, England, United Kingdom
    • 385 employees
  25. 25
    Our Future Health UK· London, England, United Kingdom
    • 375 employees
    • Founded 2020

Find engineers at AI companies in London

London has long been a hub for AI, and the list above ranks the largest AI companies headquartered there by current headcount, drawn from public LinkedIn and Crunchbase records. With 649 matching companies in our index, this is a good map of where the AI talent in Londonlives — useful whether you’re recruiting, partnering, or sizing a market.

The biggest AI companies in London tend to be the gravitational centres for specialised talent — senior engineers, ML researchers, applied scientists, designers — while the smaller ones compete on speed, equity, and proximity to founders.

Refolk converts this list into a live search. Ask for “AI engineers in Londonhiring senior staff” or “founders of AI companies in Londonwho left in the last 12 months” and Refolk returns a ranked shortlist with the evidence that earned each person a spot.

How this list is built

Refolk pulled AI companies headquartered in London from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 10 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 06:34:27 GMT

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