Jonathan Cook accepts instructions across Chambers' core practice areas.

Jonathan has experience in the Employment Tribunal, Employment Appeal Tribunal, County Court and High Court acting for both Claimants and Respondents/Defendants. He has acted in a number of complex and high value discrimination and whistleblowing cases.

Jonathan is developing a broad appellate practice and has appeared successfully as sole counsel in the EAT in a number of cases.

He also has experience of advising senior executives in complex matters including conflict of laws and share scheme rules.

Jonathan acts in personal injury and clinical negligence cases, including fast track and multi-track claims. He also assists with catastrophic injury cases. He is currently instructed as second junior counsel, led by Michael Rawlinson KC and Daniel Lawson, in High Court claims brought by firefighters injured in the Grenfell Tower Fire.

He is frequently instructed to appear against more senior opponents, including Queen's Counsels.

Before coming to the Bar, Jonathan undertook a PhD in Politics and International Studies at the University of Cambridge, where his research focused on US politics and foreign policy during the Cold War. He combined his studies with a career as an international track and field athlete, representing England at senior international level in the 800m and finishing 6th in the 1500m at the 2016 UK Olympic Trials. Currently, he referees rugby union at National League level for the RFU.

Inns of Court Gray's Inn, David Karmel Entrance Award for the GDL (2014)

Gray's Inn, Bedingfield Scholarship for the BPTC (2016)

University of Cambridge Jesus College Foundation Scholarship (2008)

Sir James Knott Bursary (2009)

CHESS PhD Scholarship (2010)

Sir Arthur Marshall Scholarship (2013 and 2014)

Research Awards Gerald R. Ford Foundation Scholarship (2009)

Dwight D. Eisenhower Foundation Scholarship (2011)

Northumbria University Ward Hadaway Prize – best GDL performance by a distance learning student (2015)

Bond Dickinson Prize – best overall GDL performance (2016)

Northumbria Law School Ben Hoare Bell Contribution Roll (2016)

Trinity Chambers Prize – best overall BPTC performance (2017)

Zenith Chambers Prize – best BPTC performance in Opinion Writing (2017)

Northumbria Law School Dean's Award for the BPTC

Industrial Law Society

Personal Injuries Bar Association

Employment Lawyers Association

Chambers & Partners 2025: (Employment) "Jon is someone that I would recommend without hesitation."

"He is a pleasure to deal with, highly responsive and strategic."

"Jon has outstanding client care skills and is highly regarded by clients."

"Jonathan's cross-examination and document management in court is especially good."

Legal 500 2025: (Employment) “His mastery of the law in action is really impressive as is his preparation.”

Chambers & Partners 2024: (Employment) “Jonathan Cook is a reputable choice of counsel acting for both claimants and respondents in employment disputes. He is adept at handling disability discrimination and constructive dismissal claims, with notable experience across the Employment Tribunal and the Employment Appeal Tribunal.”

“Jon is simply superb in really difficult tribunal matters. His cross-examination and advocacy brings out exactly the characteristics which go a long way to proving cases."

"He is very polished, on the detail and all over the documents. He is an incredibly efficient advocate, never misleading on his points."

"Jon sets out his arguments clearly and thoroughly; he writes impressive submissions. He assists his clients with strong advocacy, being composed and confident."

BA, History, University of Cambridge, 2008 (First Class)

MPhil, Historical Studies, University of Cambridge, 2009 (Distinction Equivalent)

PhD, Politics and International Studies, University of Cambridge 2015

GDL, Northumbria University, 2016 (Distinction)

BPTC, Northumbria University, 2017 (Outstanding)

Chapters on "Proof of Negligence" and "Human Rights" in Lewis and Buchan (eds.), Clinical Negligence: A Practical Guide (forthcoming, 2019)

"Morrisons' Liability for Rogue Employee: an Apple of Discord", PLC Magazine, December 2018

• Jagex Ltd v McCambridge [2020] IRLR 187, EAT – Successful representation of the Claimant in the EAT. Resisted the Respondent's appeal against the Tribunal's approach to contractual construction and findings on wrongful dismissal and Polkey. A narrow point on contributory conduct was remitted to the same Tribunal.

• Sanha v Facilicom Cleaning Services Limited UKEAT/0250/18 – Represented the Claimant at first instance in successful claims for unfair and wrongful dismissal, unlawful deductions from wages and unpaid holiday pay. Successful appeal to the EAT against the Tribunal's findings on contributory conduct and mitigation on a number of grounds including perversity. The EAT substituted a finding that the Claimant was entitled to his compensatory award in full. The Respondent's cross-appeal was dismissed.

• Josic v Alto Automotive Ltd UKEATPA/0656/18 – Represented the successful Respondent in the Claimant's appeal against Registrar's Order. The EAT held that the strict application of time limits for lodging a notice of appeal to a litigant in person did not infringe Article 6 ECHR.

• Kul v Home House Ltd – Successfully represented the Claimant in a disability discrimination and unfair dismissal claim which involved a number of complex legal issues, including the applicability of the doctrine of frustration in cases of long-term absence. Respondent represented by Queen's Counsel.

• X v Y – Succeeded at trial on liability in a disability discrimination claim for a Claimant who suffered an exacerbation of his PTSD as a result of the Respondent's handling of a redundancy process. Substantial six figure settlement prior to the remedy hearing.

• V v H – Instructed on behalf of a Respondent GP practice in ongoing Employment Tribunal litigation brought by a trainee GP against multiple Respondents. The claim is pleaded at a value of in excess of £2 million and is listed for a seven week trial on liability.

• W v H – Junior Counsel for the Claimant (led by Tom Croxford KC) in complex and high value claims for whistleblowing, unfair dismissal, discrimination and equal pay brought by a former senior EMEA executive against a US-headquartered multinational.

• R v S – Junior counsel (led by Paul Gilroy KC) acting for the former chief executive of a professional football club in a multi-million pound claim and counterclaim in the High Court.

• Grenfell Tower Litigation – Instructed as second junior (led by Michael Rawlinson KC and Daniel Lawson) in ongoing High Court personal injury claims brought by a large group of firefighters involved in the response to the Grenfell Tower Fire.