Working memory plays a key role in supporting children's learning over the school years, and beyond this into adulthood. It is proposed here that working memory is crucially required to store information while other material is being mentally manipulated during the classroom learning activities that form the foundations for the acquisition of complex skills and knowledge. A child with a poor working memory capacity will struggle and often fail in such activities, disrupting and delaying learning. The aim of this review is to present the case that working memory makes a vital contribution to classroom learning. Following a brief introduction to working memory and its assessment, links between working memory skills and scholastic progress is reviewed and illustrated. Next, the classroom behaviour of children with very poor working memory functions, and in particular their characteristic failures in learning activities, is described. Finally, the implications of this research for classroom practice is considered; this includes an intervention programme designed to improve learning outcomes for children with poor working memory function that is based on the theoretical analysis of working memory and learning advanced here.