Thomas Williams KC specialises in commercial and chancery litigation, and international arbitration.
He is an experienced advocate before courts and arbitral tribunals. He appears frequently in the High Court (including the Chancery Division and the Commercial Court) and the Court of Appeal. He has been lead counsel in arbitrations governed by the major institutional rules, and in ad hoc arbitrations under the Arbitration Act 1996.
Thomas’s litigation practice involves a wide range of commercial, corporate, insolvency and regulatory matters, often with an international element. He has considerable experience of the enforcement of judgments and arbitral awards, and frequently works with lawyers in other jurisdictions. He has significant experience of cases in the Qatar International Court (both at first instance and on appeal), and the Qatar Financial Centre Regulatory Tribunal. The focus of his arbitration practice is on complex commercial and construction disputes.
Thomas sits regularly as an arbitrator. He is a member of the panel of arbitrators of the ICC, the LCIA, the SCC, the Shanghai Arbitration Commission, the China International Economic and Trade Arbitration Commission, the Qatar International Centre for Conciliation and Arbitration, the Mumbai Centre for International Arbitration, and the Madras Chamber of Commerce. He has also undertaken an expert determination in the context of a major construction project in Qatar. Thomas takes appointments as a mediator, and recently successfully mediated an employment dispute involving a financial institution in London.
From 2017 to 2023, Thomas was a member of the Disciplinary Panel of the Bar Tribunals and Adjudication Service, in which capacity he served on tribunals to determine disciplinary charges against member of the Bar, both at first instance and on appeal. In January 2025, he was appointed a Chair of the Employment & Discrimination Tribunal in Guernsey, for a 3-year term.
Thomas is consistently recognised in the leading legal directories. The 2022 and 2023 editions of Legal 500 and Chambers Global described him as a “fantastic lawyer” who is “very fast in grasping the points presented to him”, with “the ability to put forward arguments succinctly and persuasively”, and as “a warm and dynamic character” with “really good soft skills”. In 2025, Chambers Global stated: “He writes superbly. His ability to research difficult pieces of law is unparalleled. His pleadings are technically accurate and wonderful to read.” The 2025 edition of Legal 500 notes: “Thomas is a hugely experienced and capable advocate, and has an impressive understanding of regional law and practice, having worked in Qatar for a number of years. He stands out on technical legal points, meticulously researching case law and principles.” Chambers Global, 2026 says of him: “There is no other barrister I’m aware of who understands Qatari rules and authorities better than him. He’s a very very safe pair of hands.” Legal 500, 2026 describes him as “A clear and very focused advocate, who pursues and develops the best points in his written submissions and targets the weaknesses in the other side’s case. Very good at managing a wealth of documentary material and identifying the critical evidence.”
Commercial, Company and Insolvency Litigation
Thomas has a broad commercial and company practice. He is experienced in claims for breach of commercial contracts, joint venture disputes, fraud, and claims for knowing assistance and breach of trust. He has also enforced judgments in the English High Court and abroad. He has sought and resisted the winding-up of companies, including obtaining injunctions to restrain the presentation of statutory demands and winding-up petitions, and advised liquidators on claw-back remedies. He successfully presented the first creditor’s winding-up petition in the Qatar International Court. He also has considerable experience of personal insolvency.
Recent and ongoing instructions include:
- Representing a company in resisting an application for an administration order (His Honour Judge Cawson KC (as he then was), Chancery Division, Manchester). There were complex legal issues as to whether the company was able to pay its debts, in the context of authorities (including decisions of the Supreme Court) relevant to that test as applied to start-up companies.
- Representing the claimant in a complex, 9-day fraud trial arising from a deed of undertaking (His Honour Judge Halliwell, Circuit Commercial Court, Manchester).
- Representing a company in resisting a petition under s.994 of the Companies Act 2006 (Companies Court, London). The matter settled before trial.
- Representing a company in proceedings against a director for breach of fiduciary duty, including an application for injunctive relief (His Honour Judge Berkley, Circuit Commercial Court, Bristol).
- Representing an insolvency practitioner in resisting a seminal claim by successor IPs for an assignment by the Insolvency Practitioners’ Association of the bond provided by him under s.390(3) of the Insolvency Act 1986 (His Honour Judge Rawlings, Chancery Division, Birmingham). The claim was brought on the supposed footing that the bond was held by the IPA on bare trust for the estates.
- Representing an English company against Dubai and Abu Dhabi companies, in a claim for commission arising from a corporate sale (His Honour Judge Pelling KC, Circuit Commercial Court, London).
- Representing the defendant in proceedings for fraud and breach of fiduciary duty (Chancery Division, Birmingham).
- Representing the defendant in proceedings brought against it by the alleged assignee of debts, in the context of the sale and supply of goods (Circuit Commercial Court, Liverpool).
- Representing a Ghanian bank in enforcing an English judgment in India, including in the Indian Supreme Court, under the Indian Insolvency and Bankruptcy Code 2016. This was the first case in which a foreign judgment had been used as evidence to found a petition under the Code.
- Representing a prominent Qatari businessman in a claim in the Qatar International Court, in relation to a dispute with a QFC-incorporated financial services company (Justices Lord Hamilton, Helen Mountfield KC and Fritz Brand SC). Thomas also made seminal applications on the claimant’s behalf for strike out and debarring orders.
- Representing an English supplier of energy products in winding-up proceedings in the Qatar International Court against a QFC-incorporated energy consultancy, arising out of an ICC arbitration (Justices Lord Hamilton, Ali Malek KC and Rashid Al-Anezi). This was the first creditor’s petition in the Court.
- Representing English defendants in a liability trial in the Qatar International Court, arising from the sale of a BVI company under an SPA (Justices Lord Hamilton, Helen Mountfield KC and Fritz Brand SC). The case also involved having to resist applications for a third-party debt order, a freezing injunction and security for costs.
- Representing an English businessman in proceedings brought by the QFC Regulatory Authority, including appeals against liability and sanction before the Regulatory Tribunal of the QFC (Sir William Blair, Chairman, and Justices Gopal Subramanian SC and Muna Al-Marzouqi), and the Appellate Division of the Qatar International Court (Lord Thomas, President, and Justices Chelva Rajah SC and Laurence Li SC).
- Representing an Australian businessman in a claim for unpaid wages and commission against a QFC company in the Qatar International Court (Justices Frances Kirkham CBE, Helen Mountfield KC and Fritz Brand SC). Thomas later represented the claimant in seminal contempt proceedings against the defendant, which established the applicable principles under QFC law (Justice Muna Al-Marzouqi).
- Representing company directors in proceedings brought by a former corporate shareholder in the Qatar International Court (Justices Ali Malek KC, Fritz Brand SC and Yongjian Zhang). The case involved consideration of whether the regulatory laws, rules and regulations of the QFCRA are actionable in private law proceedings (as with s.138D of FSMA 2000); if the usual rule that directors’ duties are owed to the company, and not to shareholders, is displaced; the principle of reflective loss; and the rule in Foss v. Harbottle. Within the same proceedings, Thomas made a seminal application for the defendant for security for costs, which created new law in the QFC as to the Court’s jurisdiction to award security for costs and the proper test to be applied.
- Representing the Qatar Free Zones Authority in proceedings in the Qatar International Court to contest the jurisdiction of the Qatar International Court over claims brought against it (Justices Lord Hamilton, Ali Malek KC and Muna Al-Marzouqi).
- Representing Cambridge University in a seminal case before the Appellate Division of the Qatar International Court, on the question whether the Court has opt-in jurisdiction (Lord Thomas, President, and Justices Sir William Blair and Hassan Al-Sayed).
Arbitration and Arbitration-related Litigation:
Recent and on-going instructions include:
Commercial arbitration
- Representing an English financial services company against a Portuguese bank, in an ICC arbitration arising out of a loan transaction.
- Representing a Spanish party to a JV in an LCIA arbitration against its Qatari former JV partner, concerning the profits arising from the development of a food facility in Qatar.
- Representing a Qatari party to a JV in an ICC arbitration against its Irish JV partner, concerning the profits arising from a number of major infrastructure projects in Qatar.
- Representing the US party to a JV in an ICC arbitration against its Saudi Arabian JV partner, concerning the profits arising from a construction project in Saudi Arabia.
- Representing a Nigerian party to a JV in an ICC arbitration against its Nigerian JV partner, concerning the purchase of a formerly government-owned electricity company in Nigeria.
- Representing Lebanese and Iraqi individuals in an LCIA arbitration against a commercial fishery in Sierra Leone, relating to a ship finance facility.
- Representing a Lebanese individual in an LCIA arbitration against the Iraqi owner of a power plant in Iraq, arising out of a consultancy agreement.
- Representing Qatari hotel owners in a SIAC arbitration, arising from a hotel management contract.
Construction arbitration
- Representing a Qatari employer in an ICC arbitration against a Qatari project manager, in relation to the construction of a shopping mall in Doha.
- Representing a Qatari MEP sub-contractor in an ICC arbitration against an Indian contractor, concerning the construction of a major energy facility in Doha.
- Representing a Qatari sub-contractor in an ICC arbitration against a Qatari employer, arising from core and shell works carried out as part of a major residential and commercial building project in Doha.
- Representing an Italian steel sub-contractor in an ICC arbitration against an Italian contractor, arising from the construction of a stadium in Doha.
- Representing an Indian contractor in three ICC arbitrations, case managed and heard together, against a Chinese steel sub-contractor, concerning the construction of a stadium in Doha.
- Representing an Indian sub-contractor in an ICC arbitration against a Qatari contractor, concerning the construction of a prominent mixed-use development in Doha.
- Representing a Qatari sub-contractor in an ICC arbitration against a Qatari contractor, arising from the construction of a major energy plant in Qatar.
- Representing a Malaysian employer in an ICC arbitration against a Malaysian sub-contractor, concerning the construction of a petrochemical plant in Malaysia.
- Representing a Qatari contractor against a Qatari sub-contractor in an ICC arbitration, arising from the construction of a hotel in Qatar.
Arbitration-related litigation
- Representing a party in the Qatar International Court to enforce a foreign arbitral award (Justices Fritz Brand SC, Helen Mountfield KC and James Allsop AC). The proceedings included seeking injunctive relief and resisting a jurisdiction challenge.
- Representing a party in the Commercial Court, resisting a challenge under s.68 of the Arbitration Act 1996.
- Enforcing an arbitral award in England on behalf of a Qatari entity.
- Enforcing an arbitral award in England against an African country.
- Representing a foreign government in the Commercial Court, to set aside orders of the English court permitting enforcement of an arbitral award.
Arbitrator Appointments
Recent and on-going appointments include:
- Appointed as sole arbitrator in a Doha-seated QICCA arbitration between a Qatari contractor and Qatari sub-contractor, arising from a contract for landscaping works in a residential development in Qatar.
- Appointed as co-arbitrator in a London-seated ICC arbitration between an English contractor and an Italian MEP sub-contractor, arising from the construction of a building on a military site in the Middle East.
- Appointed as sole arbitrator in a Doha-seated ad hoc arbitration between the main contractor and a sub- contractor, involving the construction of a tower block in Qatar.
- Appointed as co-arbitrator in a London-seated ICC arbitration between a US company and a Norwegian company, arising from a contract for the supply of under-sea drilling equipment.
Education
- St John’s College, Cambridge: BA (2000); MA (2005) (Law; McMahon Scholar; Choral Scholar).
- Durham University: LLM (International Law and Human Rights Law) (2001).
Bar Admissions
- England & Wales (Barrister, Lincoln’s Inn): 2002.
- Eastern Caribbean Supreme Court (British Virgin Islands): 2010.
- Astana International Financial Centre Court: 2025.
Publications
- The Prague Rules: Kiev Arbitration Days (2019).
- India as an arbitration hub: webinar with the Madras Chamber of Commerce Mediation, Arbitration and Conciliation Centre (2020).
- Reimbursement of a substituted payment of the advance on costs: webinar with the Madras Chamber of Commerce Mediation, Arbitration and Conciliation Centre (2021).
- COVID-19’s impact on the Construction industry: webinar at the Paris Arbitration Week (2021).
- The Role of Experts in Arbitration: CIArb Qatar Conference (2023).
- Liquidated damages in construction arbitrations: presentation to Simmons & Simmons (2024).
- Damages for breach of warranty: Kings Chambers Commercial Series webinar (2025).
- The use of experts in construction arbitration: seminar with Quantum Global Solutions, Istanbul (2025).
- QFC Court seminar: Bar MENA event, Serle Court Chambers (2025).
- Legal Professional Privilege and SAR reporting obligations under the Proceeds of Crime Act 2002: presentation to the Isle of Man Law Society (2025).
Privacy Notice
Please see Thomas’ Privacy Notice here.
ICO Registration Number: ZB667029
BSB & VAT Information
Registered Name: Thomas Alfred Guy Williams KC
VAT Number: 458905551

