Self-regulation has long been seen as a desirable but difficult to achieve instructional aim. This is particularly true of online learning, where users have limited instructional support and where attrition rates tend to be greater than in face-to-face teaching. This paper examines the nature of self-regulation, identifying affective and cognitive skills that make for self-regulated learners. The broad psychological states of metacognition and self-concept are identified as well as the motivational and cognitive processes that underpin them. The volitional, learning, and regulatory strategies that learners use are delineated. These are placed within the context of online learning. Aspects that characterize learning environments that support self-regulation are identified, and suggestions are made as to how self-regulation can best be enhanced within online courses. (Contains 17 references.) (Author/AEF)