LAWYER PROFILE

Mark Sansom

UK 2026

Freshfields

Ranked in 1 practice area

Competition Law: Litigation

London (Firms)

12 years ranked

About

Provided by Freshfields

UK

Practice Areas

Mark is a market-leading competition litigator with an unsurpassed track record of defending competition damages claims, including collective proceedings. He has represented clients in many of the most important and highest-profile competition damages litigation cases and collective proceedings in the UK Competition Appeal Tribunal, High Court and appeal courts, including acting for the defendants in Merricks v Mastercard, Gutmann v LSER & GTR, Gemalto v Infineon and BritNed v ABB. He frequently coordinates competition litigation and investigations globally and has been recognised internationally as a leading antitrust litigator and thought leader.

Career

Mark joined Freshfields in 1999. He became a partner in 2011. He previously led Freshfields’ London competition litigation team and London Dispute Resolution practice, and is now, alongside fully maintaining his practice, Managing Partner of the firm’s London and Dublin offices.

Chambers Review

Provided by Chambers

Chambers Guide to the Legal Profession

Competition Law: Litigation - London (Firms)

Band 1

Individual Editorial

Mark Sansom stands out for his representation of defendants in high-profile follow-on damages claims, including acting on some of the most significant class actions currently before the CAT. He acts as the managing partner of the Freshfields London and Dublin offices.

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Strengths

Provided by Chambers

Mark Sansom is a first-class lawyer and highly personable, he's a pleasure to work with.
Competition Law: LitigationChambers Guide to the Legal Profession
He is an outstanding competition lawyer, who is highly knowledgeable, commercially astute and an impressive tactician.
Competition Law: LitigationChambers Guide to the Legal Profession
Mark Sansom has a true depth of experience, he works on a lot of these litigation cases and is able to advise on these types of cases.
Competition Law: LitigationChambers Guide to the Legal Profession
He is intellectually rigorous, extremely courteous and a pleasure to work with.
Competition Law: LitigationChambers Guide to the Legal Profession