JUNIOR PROFILE

Theo Barclay

UK Bar 2026

4 New Square Chambers

Ranked in 4 practice areas

Costs Litigation

All Circuits

3 years ranked

Intellectual Property

London (Bar)

2 years ranked

Sport

London (Bar)

3 years ranked

Professional Negligence

London (Bar)

2 years ranked

About

Provided by 4 New Square Chambers

Practice Areas

Theo Barclay’s practice encompasses business disputes, sports law, intellectual property and costs law. He appears before domestic and international tribunals, with current and recent cases in the Supreme Court, Court of Appeal, High Court, LCIA and SIAC tribunals.

Theo’s commercial practice is wide-ranging, spanning civil fraud, banking and finance, intellectual property, corporate and professional negligence litigation and arbitration. His sports law practice is similarly broad, including regulatory and disciplinary issues, player/agent disputes, IP disputes and commercial litigation in a sports context. He also specialises in costs law, with a particular focus on litigation funding disputes and solicitor/client matters.

His work is frequently international in nature, including international arbitration and English Court litigation involving foreign law.

He has appeared in leading cases across his areas of expertise, including in the Supreme Court and Court of Appea

Professional Memberships

Theo is a member of COMBAR, the British Association of Sport & Law, the PNBA and the Financial Services Law Association.

Chambers Review

Provided by Chambers

UK Bar

Costs Litigation - All Circuits

Band 3

Individual Editorial

Theo Barclay advises on a full range of costs matters. He has in-depth experience in the sector, having appeared in several high-profile costs cases in recent years and at various levels of court including the Supreme Court. He also regularly appears before the Senior Courts Costs Office. Barclay acts in cases both led and unled, and has an international element to his costs practice.

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Intellectual Property - London (Bar)

Band 3

Individual Editorial

Theo Barclay is a talented and experienced barrister attracting ample praise for his soft IP practice with a particular adeptness in brand litigation. He focuses on trade mark infringement cases and frequently appears in the IPEC and Court of Appeal.

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Professional Negligence - London (Bar)

Band 4

Individual Editorial

Theo Barclay acts for claimants and defendants in a variety of professional negligence claims. He is particularly adroit in handling claims against tax advisers and accountants arising out of failed tax schemes.

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Sport - London (Bar)

Band 4

Individual Editorial

Theo Barclay is a strong barrister highlighted for his expertise in football, where he frequently acts on behalf of high-level players and clubs.

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Strengths

Provided by Chambers

He is very commercial in his outlook and is both bright and highly capable.
Costs LitigationUK Bar
He was excellent: extremely clever, diligent in his approach and able to craft coherent persuasive arguments out of difficult subject matter. He’s also extremely pleasant to work with.
Intellectual PropertyUK Bar
Theo is a force to be reckoned with. The IP Bar needs to wake up and be more commercial. It's Theo's commercial instincts that make him so good in the area.
Intellectual PropertyUK Bar
Theo is an exceptional barrister, both legally and commercially. He has a brilliant mind and a fantastic ability to work through and solve highly complex legal issues. He is extremely hard-working.
Intellectual PropertyUK Bar
Theo Barclay is really, really intelligent but also simplifies things incredibly well. He's very user-friendly and makes himself very available.
Professional NegligenceUK Bar
Theo Barclay is brilliant at hearings, a great advocate in both written and oral submissions. He gives honest advice and is very impressive in the courtroom.
Professional NegligenceUK Bar