Siti Zubaidah Ismail is an academic specialising in Islamic criminal law and criminal justice, with particular expertise in the development and implementation of Islamic criminal law in contemporary Muslim societies. She holds a Bachelor of Shariah from Universiti Malaya, a Master of Comparative Laws from the International Islamic University Malaysia (IIUM), an LL.M. from the University of Birmingham, United Kingdom, and a PhD from Universiti Malaya.

Her principal research interests lie in Islamic law and criminal justice in contemporary Muslim countries, particularly in Southeast Asia. Her scholarship examines the application of Islamic criminal law within society and the evolving legal and institutional frameworks governing its implementation in Malaysia, Indonesia and Brunei Darussalam. Her current research explores the intersection between Islamic punishment and human rights, including the potential of diyat as an alternative to the death penalty and its possible application as a basis for determining compensation or insurance quantum in road traffic accident cases in Malaysia. Her research also extends to the interaction between Islamic law and contemporary social issues, including the legal and institutional management of new Muslim converts, inter-religious marriage, religious status and freedom of religion.

She has held a number of international academic appointments. She was Visiting Fellow at the Asian Law Institute, National University of Singapore in 2010; Visiting Scholar at the Faculty of Law, Universitas Indonesia in 2016; Visiting Lecturer at Universiti Islam Sultan Sharif Ali (UNISSA), Brunei Darussalam; Visiting Fellow at the International Institute of Advanced Islamic Studies (IAIS) Malaysia in 2022; and Visiting Scholar at the Faculty of Law, Ankara Yıldırım Beyazıt University, Türkiye in 2025. She was also appointed Visiting Professor at the Faculty of Law, Universitas Brawijaya, Malang, Indonesia, under its 3-in-1 programme in 2025, and Visiting Lecturer at UIN Raden Fatah, Palembang, Indonesia, for the 2026/2027 academic session.

Her international academic recognition includes the Asian Universities Alliance (AUA) Scholars Award 2019 and the Universitas Indonesia UI-RESOLV Visiting Scholar Award 2016. From 2023 to 2024, she served as an Honorary Fellow at the Institute of Islamic Understanding Malaysia (IKIM).

She has extensive experience in academic leadership, postgraduate supervision and research management. She served as Head of the Department of Shariah and Law from 2011 to January 2016, Deputy Dean of the Humanities and Ethics Research Cluster, Universiti Malaya in 2018, and Deputy Director for Research and Development from 2019 to 2021. She has supervised approximately 20 PhD and 40 Master's students, contributing significantly to the development of emerging scholars in Islamic law, Shariah and related areas.

Beyond academia, she contributes her expertise to the development and reform of Islamic law in Malaysia. She is a member of the Majlis Agama Islam dan Adat Melayu Perak (MAIPk) for the 2024–2027 term and a member of the Law Committee of the Majlis Agama Islam dan Adat Istiadat Melayu Kelantan (MAIK) since 2024. Through these appointments, she has contributed to the review and amendment of Shariah legislation, including the Islamic Family Law Enactment 2002 and the Shariah Criminal Offences Enactment 2019. These roles reflect the translation of her academic expertise into legal reform, institutional development and public policy.

Her societal engagement is particularly significant in the field of human rights advocacy and civil-society engagement. She has served as a Senior Research Fellow at the Centre for Human Rights Research and Advocacy (CENTHRA) since 2017 and as a Senior Fellow of the Malaysian Alliance of Civil Society Organisations in the UPR Process (MACSA). Through MACSA, she contributes to the preparation of civil-society submissions for Malaysia's Universal Periodic Review (UPR) before the United Nations Human Rights Council in Geneva.

A prolific scholar, she has published more than 170 academic articles and other scholarly works and is the author of five books. Her book Undang-Undang Kesalahan Jenayah Syariah di Malaysia received the Universiti Malaya Excellence Award in 2018 and the Hadiah Karya Ilmiah 2019 from Dewan Bahasa dan Pustaka. She was also awarded the Anugerah Penulisan Artikel Terbaik dalam Jurnal Hukum 2019 by the Department of Syariah Judiciary Malaysia (JKSM).

Through her scholarship, postgraduate supervision, international academic engagement, institutional leadership, legal reform work and human-rights advocacy, her work reflects a sustained commitment to advancing the understanding and contemporary development of Islamic criminal law and criminal justice, particularly within Malaysia and the wider Southeast Asian region.