Leonard specialises in public law and human rights, public international law, sanctions, data protection law, regulatory and disciplinary law, sports law, public inquiries and immigration law.
Leonard’s clients include Governments, Government Departments, individuals, companies, regulators, regulated professionals and athletes (including Olympians).
He has extensive advocacy experience and frequently appears led and unled in the High Court and in Tribunals, including against leading counsel, and in cases where witnesses are vulnerable.
Leonard is recognised in both the Legal 500 and Chambers UK.
In addition to England and Wales, Leonard is called to the Bar of the British Virgin Islands.
He is currently appointed a member of:
- the Attorney General’s London Civil Panel (C-Panel)
- the Attorney General’s Public International Law Panel (C- Panel)
- the Government of the British Virgin Islands Panel of Counsel
Examples of Leonard’s recent work include:
- acting for the Department for Energy Security and Net Zero in an appeal against the Information Commissioner before the First-tier Tribunal (General Regulatory Chamber)
- acting for the Government of the British Virgin Islands in a substantive Judicial Review against a judicial decision
- acting for an accountancy regulator in disciplinary proceedings against one of its members having been sanctioned by the UK government
- acting for the Secretary of State for the Home Department in a substantive Judicial Review where the applicant (a convicted terrorist) challenged the decisions to refuse him indefinite Leave to Remain and to grant him 6 months leave under the Restricted Leave Policy
- acting in an arbitration for two Olympians accused of abuse by their National Governing Body
- acting for the Secretary of State for the Home Department in a statutory appeal against deportation of a convicted terrorist, who was a minor at the time of offending
- acting for a doctors’ practice in a data protection claim following a request for erasure of a patient’s medical records
Directory Quotes
Administrative & Public
Leonard has been appointed a member of the Attorney General’s C Panel (London) from 1 September 2026. He has significant experience in public law and is regularly instructed in judicial review proceedings.
His public law practice has a particular focus on sanctions, detention, human trafficking, asylum, human rights and judicial review claims against regulatory bodies. His clients include individuals, government departments, regulators and regulated professionals.
He regularly acts in high-profile litigation involving the UK Government and appears unled in the Administrative Court.
Professional Discipline & Regulation
Leonard acts for both regulatory bodies and regulated professionals. He has significant experience in matters before the Association of Chartered Certified Accountants, Architect Registration Board, the General Medical Council, the General Optical Council, the General Pharmaceutical Council, the Nursing and Midwifery Council, the Health Care Professional Council.Leonard is often instructed cases to advise and represent at the investigatory stage. He is experienced and qualified in handling of vulnerable witnesses.He has particular expertise in public and human rights law, public international law, sanctions, regulatory law, sports law, data protection law, commercial law, personal injury, public inquiries and immigration law. His clients include individuals, companies, government departments, regulators, regulated professionals and athletes.
Sport
Leonard represents athletes (including Olympians) in all manner of regulatory issues relating to sport law, such as deselection appeals and abuse claims.
Recent examples include:
- Acting for an athlete in a challenge to deselection.
- Acting for an athlete in a change of National Governing Body
- Acting in arbitration proceedings for Olympians facing allegations of abuse brought by their national governing body.
- Acting for an athlete in a challenge to arbitration jurisdiction.
- As a qualified arbitrator, he has an in depth knowledge of arbitral procedures used in sports law.
Leonard is also a member of the Sport Resolution Pro Bono Panel.
Notable Cases
Education & Qualifications
- PGC (International Dispute Resolution).
- LLM (Public International Law).
- LLB (Hons).
- BA (Hons).
Appointments & Memberships
- MCIArb.
- ALBA.
- ARDL.
- Sport Resolutions Pro Bono Panel.
Personal Interests
Leonard is an avid guitarist and enjoys writing and playing music.
To instruct Leonard Wigg or obtain more information
Our clerking team, led by Chief Executive & Director of Clerking, Paul Cray, will be pleased to help with any enquiry regarding Leonard Wigg, including suitability, availability, and fees. The team offers responsive, commercially focused, and highly professional support.