Educators worldwide have embraced task-based language teaching (TBLT) because of its potential to promote rich language development through motivating and engaging tasks (Adams & Newton, 2009; Pham & Nguyen, 2018). Technology-mediated task-based language teaching (TMTBLT) is situated at the intersection of these two fields, and grew out of the need to ground CALL research in second language acquisition (SLA) theory and sound empirical frameworks (Chapelle, 1997, 2009). TMTBLT research explores how technology facilitates language development and performance through tasks, and how technology contributes to our understanding of different features of TBLT (see Ziegler, 2016 for a review). This chapter reviews research on the role of technology in encouraging affective engagement during the performance of technology-mediated language tasks. It first describes Egbert et al.’s (2019) model of engagement and Mayer’s (2005) cognitive theory of multimedia learning and then provides an overview of the literature on how technology-mediated tasks can be optimally designed and implemented from the perspective of these models. In doing so, we carve out several directions for future research on engagement in TMTBLT contexts.