The success of second language (L2) tasks relies in large part on individual learners’ willingness to communicate (WTC) during the course of the task. Particularly relevant is situated L2 WTC, or the readiness to enter into discourse at a particular time with a specific person or persons using the L2. Situational conditions, such as the immediate task demands, can give rise to changes in self-confidence and the desire to communicate with specific interlocutors, thus affecting WTC during task performances. These situated factors are distinguished from more stable WTC influences – motivational propensities and social and individual factors that operate in the background to impact L2 communication behavior. This chapter will first provide an overview of the WTC pyramid model and discuss its relevance to task-based language teaching (TBLT). It will then review research related to trait L2 WTC, situated WTC, and dynamic WTC, focusing on the more recent work that has examined fluctuations in L2 WTC during tasks, which are influenced by multitudes of individual and contextual factors. The chapter concludes with describing a task-specific WTC model and a research agenda for investigating WTC within the context of task performances.