"Jessica has a deep understanding of administrative and public law. A brilliant advocate, she has the ear of the court and knows how to present arguments in a way which means they are heard."
"Her advocacy is sublime. She is so clear, and gets her point across so beautifully. She isn't loud and shouty but once she starts speaking, everyone listens."
A leading specialist in public law and human rights with over thirty years’ experience across a broad range of public and international law matters ranging from complex regulatory/commercial litigation and advisory work in regulated sectors: energy, water, transport, finance and education to competition/state aid, data protection, tax and administrative law related insolvency issues. She has acted in ground-breaking constitutional, environmental and human rights cases, appearing on numerous occasions in the UK Supreme Court and Court of Appeal, as well as in the Strasbourg and Luxembourg courts. Some of her higher profile cases include: Verein KlimaSeniorinnen Schweiz and Others v Switzerland [2024] ECHR 53600/20 (climate change and human rights); R (Miller & Anor) v Secretary of State for Exiting the European Union & Ors, [2018] AC 61 (Article 50 litigation); R (on the application of Mastercard Europe SA) v Payment Systems Regulator [2026] EWHC 64 (Admin) (PSR price capping powers); Re Baglan Operations Ltd [2022] EWHC 647 (Ch), [2022] BCC 884 (acted for the Official Receiver in respect of his obligations); Secretary of State for the Home Department v Watson [2018] EWCA Civ 70 (data retention and privacy).
Jessica is ranked as a Tier 1 Leading Silk in Public and Administrative Law (Legal 500), nominated for Legal 500 2024 Public Law Lawyer of the Year.
Prior to taking Silk in 2013, she was a member of all three of the Attorney General’s Panels of Counsel. She has worked in the Legal Department of the European Commission Environment Directorate in Brussels as well as in the European Court of Human Rights in Strasbourg and in the Human Rights Ombudsman’s office in Sarajevo. She is the original author and now Consultant editor of Sweet and Maxwell’s looseleaf: ‘Human Rights Practice’. Between 1992-2000 she was a member of Monckton chambers before founding Matrix chambers with 24 colleagues in May 2000. In May 2026 she was appointed to the Expert Panel of the new Independent Football Regulator. She is a Visiting Professor at LSE and Goldsmiths.
Member of Expert Panel of the Independent Football Regulator
Bencher, Middle Temple
EU Committee of the Bar Council of England and Wales
Former Chair and Member of Executive committee of Bar European Group
Fellow of the Bingham Centre for the Rule of Law
Accredited Mediator
Member of Steering Committee of international climate change litigation project, first meeting held November 2008 at Michigan Law School
Signatory of Oslo Principles on Climate Change
Member of the UNHCR panel of specialised counsel
Former executive member of Justice and the British Institute of Human Rights, of which she was also Chair.
MA (Oxon)
CPE (City University)
Dip EU Law (King’s College London)
Harmsworth Law Scholar, Inns of Court Scholar
Fluent French.
Jessica is fluent in French.
Jessica is committed to protecting and respecting your privacy. In order to provide legal services to their clients, including advice and representation services, Jessica needs to collect and hold personal data. This includes their client’s personal data and the personal data of others who feature in the matter upon which they are instructed. To read Jessica’s privacy notice in full, please see here.
"Jessica Simor KC is able to quickly analyse the key points of a case and is a recognised expert in complex, high-profile matters." "She blends immense talent and determination with an approach that makes her a joy to work with." "Jessica Simor KC is a first-rate advocate."
"She is very high profile and a good, strong advocate." "Jessica is very good."
"She is someone who genuinely cares." "She is passionate in her advocacy." "She is known by the Judges and they really listen to her." "Jessica is highly respected in the appeal courts." "Jessica has a superb advocacy style and engagement with detail."
"Jessica is a great barrister and she gives great written advice." "Her brain runs faster than others." "Jessica is a brilliant barrister."
"Jessica is pragmatic and easy to work with and she understands the broader issues rather than just the legal context."
"Jessica has a deep understanding of administrative and public law. A brilliant advocate, she has the ear of the court and knows how to present arguments in a way which means they are heard."
"Her advocacy is sublime. She is so clear, and gets her point across so beautifully. She isn't loud and shouty but once she starts speaking, everyone listens."
"Jessica has the ear of the court and knows how present arguments in a way which are heard."
"Jessica is a passionate advocate and is good on her feet. She produces written work of a high quality."
"She is responsive, knowledgeable and very good at thinking on her feet."
"She has the ear of the court." "Her advocacy is unbelievably good and her ability to get up to speed with unfamiliar areas of law is outstanding."
"A very determined advocate who is a formidable opponent."
"Fantastically clear, authoritative and powerful advocacy."
"Jessica has the ability to explain a complex situation in the most straightforward way."
"A tenacious advocate. Extremely approachable and great to work with. An excellent QC for EU law cases."
"In court she is formidable. She understood the clients concerns and put it to the court which not only showed a mastery of the case but real empathy with the clients situation."
"A very established EU law practitioner who is thorough, persuasive, good on her feet and analytical."
"An excellent lawyer who is very passionate about her work."
"She is as good as ever: precise and practical."
"She develops new approaches, and is good at finding ways of advancing the field."
"An excellent lawyer who is very passionate about her work."
"She is clearly passionate about what she does, is a straight-talker and really understands which points will resonate with the court."
"A very polished and knowledgeable advocate.” “She is an established new law expert who is calm and persuasive.” “She’s very approachable, user-friendly and good on judicial review."
"Jessica Simor is very good and thorough."
"Simor is brilliant on EU law and gets results for her clients."
"Instructed in Brexit-related Luxembourg cases."
"She has a deep and impressive knowledge base."
"Provides excellent technical and strategic advice at all times and does so in an approachable and down-to-earth manner. She is undoubtedly a subject expert in public and human rights law, and is unflappable on her feet in court.” “Very straightforward, she explains complicated things in a really simple way."
"Jessica is charming and very good at what she does."
"She excels at providing commercial and strategic advice.” “She has an incredible ability to make complex things simple and a really good sense of what points to make and advance.” “She distils complicated things into simple points very quickly, which is very helpful for clients."
"She has the ability to analyse complex issues of fact and law."
"A real master of her craft. Extremely hardworking, diligent and passionate about her cases."

"Jessica has a deep understanding of administrative and public law. A brilliant advocate, she has the ear of the court and knows how to present arguments in a way which means they are heard." "Her advocacy is sublime. She is so clear, and gets her point across so beautifully. She isn't loud and shouty but once she starts speaking, everyone listens."
Legal 500, 2024, Administrative Law and Human Rights & Chambers & Partners, 2024, Civil Liberties and Human Rights
Contact Jessica: jessicasimor@matrixlaw.co.uk | +44 (0)20 7404 3447
Contact Jessica's Practice Team (Team X): TeamX@matrixlaw.co.uk
A leading specialist in public law and human rights with over thirty years’ experience across a broad range of public and international law matters ranging from complex regulatory/commercial litigation and advisory work in regulated sectors: energy, water, transport, finance and education to competition/state aid, data protection, tax and administrative law related insolvency issues. She has acted in ground-breaking constitutional, environmental and human rights cases, appearing on numerous occasions in the UK Supreme Court and Court of Appeal, as well as in the Strasbourg and Luxembourg courts. Some of her higher profile cases include: Verein KlimaSeniorinnen Schweiz and Others v Switzerland [2024] ECHR 53600/20 (climate change and human rights); R (Miller & Anor) v Secretary of State for Exiting the European Union & Ors, [2018] AC 61 (Article 50 litigation); R (on the application of Mastercard Europe SA) v Payment Systems Regulator [2026] EWHC 64 (Admin) (PSR price capping powers); Re Baglan Operations Ltd [2022] EWHC 647 (Ch), [2022] BCC 884 (acted for the Official Receiver in respect of his obligations); Secretary of State for the Home Department v Watson [2018] EWCA Civ 70 (data retention and privacy).
Jessica is ranked as a Tier 1 Leading Silk in Public and Administrative Law (Legal 500), nominated for Legal 500 2024 Public Law Lawyer of the Year.
Prior to taking Silk in 2013, she was a member of all three of the Attorney General’s Panels of Counsel. She has worked in the Legal Department of the European Commission Environment Directorate in Brussels as well as in the European Court of Human Rights in Strasbourg and in the Human Rights Ombudsman’s office in Sarajevo. She is the original author and now Consultant editor of Sweet and Maxwell’s looseleaf: ‘Human Rights Practice’. Between 1992-2000 she was a member of Monckton chambers before founding Matrix chambers with 24 colleagues in May 2000. In May 2026 she was appointed to the Expert Panel of the new Independent Football Regulator. She is a Visiting Professor at LSE and Goldsmiths.
Member of Expert Panel of the Independent Football Regulator
Bencher, Middle Temple
EU Committee of the Bar Council of England and Wales
Former Chair and Member of Executive committee of Bar European Group
Fellow of the Bingham Centre for the Rule of Law
Accredited Mediator
Member of Steering Committee of international climate change litigation project, first meeting held November 2008 at Michigan Law School
Signatory of Oslo Principles on Climate Change
Member of the UNHCR panel of specialised counsel
Former executive member of Justice and the British Institute of Human Rights, of which she was also Chair.
MA (Oxon)
CPE (City University)
Dip EU Law (King’s College London)
Harmsworth Law Scholar, Inns of Court Scholar
Fluent French.
Jessica is fluent in French.
Jessica is committed to protecting and respecting your privacy. In order to provide legal services to her clients, including advice and representation services, Jessica needs to collect and hold personal data. This includes her client’s personal data and the personal data of others who feature in the matter upon which she is instructed. To read Jessica’ privacy notice in full, please see here.
"Jessica Simor KC is able to quickly analyse the key points of a case and is a recognised expert in complex, high-profile matters." "She blends immense talent and determination with an approach that makes her a joy to work with." "Jessica Simor KC is a first-rate advocate."
"She is very high profile and a good, strong advocate." "Jessica is very good."
"She is someone who genuinely cares." "She is passionate in her advocacy." "She is known by the Judges and they really listen to her." "Jessica is highly respected in the appeal courts." "Jessica has a superb advocacy style and engagement with detail."
"Jessica is a great barrister and she gives great written advice." "Her brain runs faster than others." "Jessica is a brilliant barrister."
"Jessica is pragmatic and easy to work with and she understands the broader issues rather than just the legal context."
"Jessica has a deep understanding of administrative and public law. A brilliant advocate, she has the ear of the court and knows how to present arguments in a way which means they are heard."
"Her advocacy is sublime. She is so clear, and gets her point across so beautifully. She isn't loud and shouty but once she starts speaking, everyone listens."
"Jessica has the ear of the court and knows how present arguments in a way which are heard."
"Jessica is a passionate advocate and is good on her feet. She produces written work of a high quality."
"She is responsive, knowledgeable and very good at thinking on her feet."
"She has the ear of the court." "Her advocacy is unbelievably good and her ability to get up to speed with unfamiliar areas of law is outstanding."
"A very determined advocate who is a formidable opponent."
"Fantastically clear, authoritative and powerful advocacy."
"Jessica has the ability to explain a complex situation in the most straightforward way."
"A tenacious advocate. Extremely approachable and great to work with. An excellent QC for EU law cases."
"In court she is formidable. She understood the clients concerns and put it to the court which not only showed a mastery of the case but real empathy with the clients situation."
"A very established EU law practitioner who is thorough, persuasive, good on her feet and analytical."
"An excellent lawyer who is very passionate about her work."
"She is as good as ever: precise and practical."
"She develops new approaches, and is good at finding ways of advancing the field."
"An excellent lawyer who is very passionate about her work."
"She is clearly passionate about what she does, is a straight-talker and really understands which points will resonate with the court."
"A very polished and knowledgeable advocate.” “She is an established new law expert who is calm and persuasive.” “She’s very approachable, user-friendly and good on judicial review."
"Jessica Simor is very good and thorough."
"Simor is brilliant on EU law and gets results for her clients."
"Instructed in Brexit-related Luxembourg cases."
"She has a deep and impressive knowledge base."
"Provides excellent technical and strategic advice at all times and does so in an approachable and down-to-earth manner. She is undoubtedly a subject expert in public and human rights law, and is unflappable on her feet in court.” “Very straightforward, she explains complicated things in a really simple way."
"Jessica is charming and very good at what she does."
"She excels at providing commercial and strategic advice.” “She has an incredible ability to make complex things simple and a really good sense of what points to make and advance.” “She distils complicated things into simple points very quickly, which is very helpful for clients."
"She has the ability to analyse complex issues of fact and law."
"A real master of her craft. Extremely hardworking, diligent and passionate about her cases."