Diana M. Thomas

Senior Partner


Diana, a senior partner in the firm, has been a lawyer for over twenty years. She has a depth of knowledge and vast experience in many areas of practice. Diana has been ranked in Chambers and Partners for seven consecutive years. In its 2020 Global Guide she was described as an “extremely experienced and well-regarded litigator” with an “extensive knowledge of the civil code.” She is noted in particular for her work with financial institutions and banks, and sources consider her a “brilliant lawyer“.

A co-head of the Litigation and Alternative Dispute Resolution Department, she has successfully represented clients at all levels of the Court including the Privy Council and settled matters at mediations or negotiations in St. Lucia, in other Caribbean islands and in the United States. She has developed and maintained legal relationships with large corporations in St. Lucia across several industries including utility providers, hotels, car dealerships, banks, insurance companies, quasi government bodies, and of course the so important individual citizen.

Diana advises extensively on commercial, banking and finance matters, probate and administration, employment and labour disputes, and regularly represents receivers and liquidators in insolvency matters. She has been appointed to act as liquidator of a local company by the Eastern Caribbean Supreme Court. With a special interest in the law of trusts, she has unparalleled expertise in the area.

She trained with the late Hilford Deterville, Q.C., first as an Associate Attorney at Caribbean Law Offices and subsequently re-joined him as a Partner at Deterville, Thomas & Co., after an eight-year stint at Peter I. Foster & Associates.

Diana maintains a pro-bono practice and is a registered provider with the Legal Aid Authority. In 2021, she served as Acting Master of the Eastern Caribbean Supreme Court. Diana is the President of the Bar Association of Saint Lucia. 


  • Litigation and Alternative Dispute Resolution

Practice Areas

  • Finance and Banking
  • Commercial and Corporate
  • Transactions/Mergers & Acquisitions
  • Bankruptcy and Insolvency
  • Trusts, Wills, Probate and Administration
  • Litigation and Alternative Dispute Resolution
  • Medical Negligence and Personal Injury
  • Employment and Labour
  • Divorce
  • Construction and Planning

Education and Bar Admissions

  • LL.B, First Class Honours, University of the West Indies, Cave Hill Campus, Barbados, 2001
  • Legal Education Certificate, Hugh Wooding Law School, Trinidad & Tobago, 2003
  • Admitted to Practice Law in Saint Lucia, 2003
  • Admitted to Practice Law in St. Kitts & Nevis, 2012
  • Admitted to Practice Law in Anguilla, 2014
  • Admitted to Practice Law in Grenada, 2016

Membership and Other

  • President, Bar Association of Saint Lucia, 2022 to present
  • Member, Bar Association of Saint Lucia, 2003 to 2022
  • Member, Integrity Commission of Saint Lucia, 2013 to 2016
  • Member Management Committee of Upton Garden Girls Centre, 2016 to 2019
  • Member, OECS Bar Association, 2018 to present
  • Student Member, Insolvency Practitioner’s Association
  • Chairperson, Protective Services Commission, 2018 to present