Siân is a specialist public law barrister with a busy practice spanning all aspects of administrative, human rights, and local government law, as well as related areas of planning and environmental law.

Siân joined Landmark Chambers in 2023 and has continued to build a busy practice spanning all aspects of administrative, human rights, and local government law, as well as related areas of planning and environmental law. She has extensive experience of working as sole counsel and as part of a team, and has appeared in more than 20 reported cases including five before the Court of Appeal and seven before the Privy Council. She has been ranked as a ‘rising star’ in administrative and human rights law in Legal 500, 2023 and 2024. Directory testimonials recognise her as “an amazing junior” and particularly as “excellent at using public law principles to craft a winning strategy in difficult cases”.

She is direct access qualified and welcomes instructions on this basis in appropriate cases across all her practice areas.

Before coming to the Bar, Siân studied law at Oxford University and worked for the Ministry of Justice as judicial assistant to Lord Justice Hamblen (as he then was) in the Court of Appeal, where she gained insight into the judicial perspective on the court’s day to day work and proceedings. Beyond her practice, Siân maintains a strong academic interest in public law. She is assistant editor of the Judicial Review journal, and is currently completing a PhD at University College London, where her doctoral research complements her practice in public law. Her work is supervised by Professor Richard Rawlings and Dr Michael Veale.