Siti Zubaidah Ismail's field of expertise is Islamic criminal law and criminal justice. She graduated with Bachelor of Shariah from University of Malaya, Master of Comparative Laws from IIUM, LL.M from Birmingham University and PhD (Malaya). Her main research interest  is on the Islamic law and criminal justice in contemporary Muslim countries, particularly in Southeast Asia. She also focuses on the application of Islamic criminal law on the society  and on the development of Islamic criminal law implementation in Malaysia, Indonesia and Brunei. Her current research is on the intersection between islamic punishment and human rights and the potential of diyat as an alternative to death penalty in Malaysia She is also active in research relating to interaction of Islamic law in society relating to new-Muslim reverts, inter-religious marriage and freedom of religion. She was Visiting Fellow at Asian Law Institute, National University of Singapore in 2010, Visiting Scholar at Faculty of Law Universitas Indonesia in 2016, Visiting Lecturer at UNISSA, Brunei, Visiting Fellow at IAIS in 2022 and Visiting Scholar at Law Faculty, Yildirim Beyazit University, Ankara Turkey in 2025. She was one of the recipients for AUA Scholars Award 2019 and Universitas Indonesia's UI-Resolv Visiting Scholar Awards 2016. From 2023-2024 she was Honorary Fellow at IKIM. She was also invited to teach her subject of expertise in Universitas Brawijaya Law School in Malang, Indonesia under 3-in-1 program in 2025. She has supervised 20 Phd and 40 masters students. She was Head of the Shariah and Law Department from 2011 until January 2016, Deputy Dean for Humanities and Ethics Research Cluster of UM in 2018 and Deputy Director for Research and Development from 2019-2021. She contributes her expertise in Islamic law as member of Majlis Agama Islam dan Adat Melayu Perak (2024-2027) and as Law Committee Member for Majlis Agama Islam Kelantan (MAIK) and advised on the amendments of shariah laws including Islamic Family Law Enactment 2002 and Shariah Criminal Offences Enactment 2019. Her contribution in the society is also significant in the area of human rights activism and advocacy. She is Senior Research Fellow with Centre for Human Rights Research and Advocacy (CENTHRA) since 2017 and Senior Fellow for Malaysian Alliance of Civil Society Organisations in the UPR Process (MACSA) assisting in preparing the civil society report for UPR Process in Geneva, Switzerland every five years. She has more than 165 articles published and the author of four books.  Her book Undang-Undang Kesalahan Jenayah Syariah di Malaysia won Anugerah Cemerlang Universiti Malaya 2018 and Hadiah Karya Ilmiah 2019 from Dewan Bahasa Pustaka. She also received "Anugerah Penulisan Artikel Terbaik dalam Jurnal Hukum 2019" by Jabatan Kehakiman Syariah Malaysia.  She is married with seven children.