The aim of this study was to examine how motivation, perceived learning support, learning engagement, and self-regulated learning strategies relate to learners' perceived learning outcomes of massive open online courses (MOOCs). An online survey was administered to 546 participants from four MOOCs. Seven types of reasons for attending MOOCs were identified, ranging from intrinsic to extrinsic motivation. One-way MANOVA revealed that learners with autonomous motivation demonstrate higher scores on perceived learning outcomes than learners with controlled motivation. In addition, multiple regression analysis methods showed that course design, interaction with instructors and peers, engagement in learning activities, and applying cognitive and metacognitive learning strategies significantly explain differences in perceived learning outcomes. Furthermore, mediation analyses demonstrated that cognitive and metacognitive learning strategies significantly mediated the relationships between motivation, perceived learning support, and learning engagement on the one hand and perceived learning outcomes on the other. Finally, practical implications are discussed and future research directions are recommended.