Catherine Simpson, Deputy Director of Guidance and Review (Martyn’s Law), Security Industry Authority (SIA)
Catherine Simpson is a senior leadership professional currently serving as the Deputy Director of Guidance and Review for Martyn’s Law at the Security Industry Authority (SIA).

In this pivotal role, Catherine is responsible for the design, mobilisation, and strategic leadership of the new regulatory function mandated by the Terrorism (Protection of Premises) Act 2025. She leads the development of regulatory guidance, outreach and review programs, ensuring the SIA is operationally prepared to protect the public and enhance security standards across the UK ready for the go-live date, supporting our regulated community.

With a career spanning over two decades in policing, Catherine brings extensive expertise to the SIA. Prior to this appointment, she served as the Head of the Policy and Guidance Department at the National Counter Terrorism Security Office (NaCTSO) and the Deputy Head of NaCTSO for two years, specialising in protective security and preparedness of venues and public spaces and terrorism. Catherine also spent 17 years as a senior forensic expert, where she managed high-profile investigations and delivered expert testimony at court.

A passionate advocate for inclusivity and talent development, Catherine was a dedicated mentor within the Women in National Security (WiNS) scheme and an active member of the Women in Security Network. She is committed to fostering high-performing, inclusive teams that drive positive cultural change and excellence in security.