Colleen is a tri-qualified solicitor and founder of Ardea International ( previously CLT envirolaw), a niche company that provides sustainability, modern slavery, business and human rights consultancy and expertise to enable companies to meet both their legal obligations and develop voluntary best practice standards. Prior to establishing CLT envirolaw, she worked as an environmental lawyer in the City of London and was recognised by The Legal 500 and Chambers as a leading environmental law practitioner.

Colleen’s indefatigable passion for combating human trafficking, particularly in business supply chains led her to found the not-for-profit organisation Finance Against Trafficking. She has spoken widely on the UN Guiding Principles on Business and Human Rights, modern slavery and sustainable business emphasising the growing overlap between best practice sustainability and the law. She is also a member of the steering group of the British Association for Sustainable Sport (BASIS). Previously, she was an executive member and trustee of the UK Environmental Law Association for seven years. She sits on the advisory board for LexisPSL Environment. She has recently been appointed to the sustainability advisory council for Positive Luxury.

As a Lecturer in environmental law at Birkbeck University, London, she recently designed and delivered a Masters course on business and human rights and international laws as they apply to multinational corporations. She is a regular contributor to the legal and professional press and has authored numerous accredited articles and chapters in books, most recently a publication on the financial drivers for embedding sustainability in a sports organisation published by Routledge in ‘Sport Management and the Natural Environment’. Her book ‘Strategic Sustainable Procurement: law and best practice‘ has been published by Greenleaf Publishing.

Dedicated to raising awareness of modern slavery, Colleen was part of the Modern Slavery Garden team which won Gold at the Chelsea Flower Show 2016 and has been nominated for an award by the Anti Slavery Awards group. She has set up an anti trafficking hub at the Towers Convent school in West Sussex.

Colleen has a LLM (with distinction) in Environmental Law from the University of Aberdeen.

Colleen Theron's picture

Areas of Practice

  • Year Qualified



    LLM (with distinction)