Kay L. O'Halloran (born 1958) is an Australian-born academic in the field of multimodal discourse analysis. She is Chair Professor and Head of Department of Communication and Media in the School of the Arts at the University of Liverpool and Visiting Distinguished Professor at Shanghai Jiaotong University (2017–2020). She is the founding director of the Multimodal Analysis Laboratory of the Interactive and Digital Media Institute (IDMI) at the National University of Singapore (NUS). She is widely known for her development of systemic functional multimodal discourse analysis (SF-MDA) and its application in the realm of mathematical discourse and multimodal text construction. Her current work involves the development and use of digital tools and techniques for multimodal analysis and mixed methods approaches to big data analytics.