Recent research points to the need for a specific research focus on language task engagement because task engagement can lead to increased motivation, persistence, satisfaction, and learner achievement (Early, Rogge, & Deci, 2014; Henri, Halverson, & Graham, 2015; Reeve & Lee, 2014); a major gap in the research in this area is the lack of a unifying model. This study responds to this gap in order to move understandings of language task engagement forward. To meet this purpose, the present study applies both descriptive and statistical data to develop and validate a model of language task engagement. The article describes the exploration of language task engagement from two main sources: (1) the large body of literature around engagement, which was used as one source of data for model-building, and (2) online surveys of student, teacher, and researcher perspectives that were collected and analyzed from multiple sources and contexts. To explain the model, the article first presents a brief justification for exploring the engagement construct, differentiating task engagement from related concepts. The paper then outlines the study methodology, presents and describes the model based on the literature and other data, and provides conclusions and recommendations.