Image of Harriet Ellis

Harriet Ellis

Litigation, Arbitration & Investigations Partner, London

"I represent clients across all sectors, defending them against group and class action litigation, as well as other high stakes litigation. I have particular experience advising on issues with overlapping civil, criminal and public law elements. I work collaboratively with clients and their teams to develop strategies and approaches that work for them".




Solicitor of the Senior Courts of England and Wales

Harriet is an experienced commercial litigator specialising in the defence of funded group and class action litigation as well as high stakes, crisis litigation. She is ranked as a Leading Individual in the Legal 500.

She works for clients across all sectors, often in close collaboration with lawyers from the firm’s other market-leading practice areas, including AFIG, Corporate and TMT in cross practice, multi-disciplinary teams. She has a particular interest in the tech and consumer sectors.

Clients describe her as strategic, pragmatic and very approachable.


Harriet has acted for clients across all sectors in a number of high profile, high stakes disputes. Highlights include representing:

  • A FTSE 100 company in its ongoing defence of securities litigation claims brought in parallel representative and group litigation proceedings;
  • Telefonica SA in its successful defence of a claim brought by the administrators of Phones4U alleging collusion amongst UK mobile network operators;
  • A global tech platform in novel threatened group litigation concerning online and offline harms;
  • The Internet Association as intervenor in Lloyd v Google before the Supreme Court;
  • A large tech company in its defence of representative proceedings concerning alleged data breaches;
  • An international private equity group defending threatened group litigation claims under the consumer credit act, amongst others;
  • Succocitrico Cutrale in connection with ongoing group litigation proceedings brought by growers alleging price-fixing and related cartel activity; 
  • A FTSE 100 company on a product liability issue which led to civil claims, a parliamentary inquiry and criminal investigation;
  • A range of clients in a number of high profile public inquiries and related civil claims, including the ongoing Covid Inquiry, the Independent Inquiry into Child Sexual Abuse, the Grenfell Tower Inquiry and the Leveson Inquiry.


  • 2001/2002 Nottingham Law School, Legal Practice Diploma with Distinction

  • 1998 – 2001 Christ Church, Oxford, Jurisprudence, First Class