University students' success in core mathematics courses has been linked to their overall academic achievement in many undergraduate programs. This finding has prompted an ongoing inquiry into the way mathematics is taught, focusing, specifically, on the university mathematics lecture-the most common instructional activity-and on the extent to which it is conducive to student engagement, regarded as key to successful learning. This dissertation reports on a multimodal study of student engagement in undergraduate mathematics lectures with the purpose to develop a context-specific understanding of student engagement, and identify and describe aspects of university mathematics teaching that impact student engagement. A theoretical and analytical framework combining concepts from discourse studies, Vygotskian sociocultural theory, situated learning, multimodality, speech theory, and gesture studies is used to investigate university mathematics teaching as a complex discursive practice. The study responds to First and foremost, I would like to thank my supervisor, Professor Natasha Artemeva, whose guidance and support have seen me through so many years of study and growth. Natasha, you have taught me so much. Thank you, for everything. To my wonderful parents, Virginia Bourget and Patrick Fogarty, thank you for always being there, for all your love and encouragement. To my partner in adventure and happiness, Hasi Eldib, your love, warmth, kindness, support, and caring are a gift. Thank you for always making summer feel close at hand. I love you. Thank you as well to all those who helped me along the way: To Professor Janna Fox and the members of my doctoral committee, Professor Sigrid Norris, Dr. Silva Ladewig, and Professor Iosif Polterovich, as well to my examiners Professor Christine Räisänen and Dr. Janet Mantler, thank you all for your time and invaluable feedback. And to my research participants, without whom this dissertation would not exist, thank you for your time and sharing. Joan Grant, Connie Wall, Tracey Wright, and Mike Barker, thank you for all that you do, every day, for the students and members of our department. Thank you for all your help. Special thanks to Claire and all the other wonderful, brilliant women with whom I have had the pleasure of sharing so many hours of hard work and writing: Christen, Codie, Janna, Lauren, Lisa, Nina, and many more. Thank you for laughing, listening, cheersing, collaborating, brainstorming, blue skying, and of course, for the countless units. I am so fortunate.