Prior studies of MOOC learners have focused almost exclusively on behavioural and social aspects of engagement. This paper extends the scope of previous studies by adopting a multi-dimensional, person-centred approach to investigate learner engagement in MOOCs. An analysis of 1,452 self-administered survey responses uncovered three prototypical categories of MOOC learners based on patterns of behavioural, cognitive, emotional and social engagement: (a) "Individually Engaged" learners, (b) "Least Engaged" learners and (c) "Wholly Engaged" learners. The study revealed significant differences among the three cohorts of MOOC participants with respect to learner factors (gender, origin, motivation), teaching context (course level, course duration, form of the assessment) and learning outcomes (course completion, perceived quality of instruction). The results of this study suggest that adopting a multi-dimensional, person-centred approach can be useful for researchers and practitioners to classify MOOC learners into subpopulations, design effective educational interventions that best engage different types of learners, and provide support and scaffolding to individuals with idiosyncratic or problematic engagement patterns. Lay Description What is already known about this topic Implications for practice and/or policyWhat this paper adds Most of the empirical research has adopted a unidimensional, variable-centred approach to explain engagement in MOOCs. Behavioural and social engagement are often used to measure MOOC engagement because they are overt and easily identifiable. A higher level of behavioural and social engagement predicts favourable MOOC learning outcomes, such as academic achievement and course completion. Cognitive and emotional engagement are often overlooked in MOOC research. The study employs a multi-dimensional, person-centred approach to investigate learner engagement in MOOCs. The study uncovers three prototypical categories of MOOC learners (n = 1,452) based on their patterns of behavioural, cognitive, emotional and social engagement. The study reveals significant differences among the three cohorts of MOOC learners with respect to learner factors (gender, origin, motivation), teaching context (course level, course duration, form of the assessment) and learning outcomes (course completion, perceived quality of instruction). To optimize engagement and learning outcomes, educators and learning designers should address MOOC participants' extrinsic motivations (e.g. academic and career needs) when configuring the teaching and learning space. Engagement and learning outcomes can be improved by making a course more intellectually stimulating. Educators and learning designers should avoid enticing enrolments by simply making the course easier. Engagement can be enhanced by incorporating assessment tasks and taking advantage of human-graded assessment strategies where appropriate. Reducing the duration of a MOOC is not the best way to increase engagement.