Linked Data principles and technologies are being investigated in various areas. In the Educational context, many studies are using Linked Data trying to solve problems of interoperability of educational data and resources, enriching educational content, and personalizing and recommending educational content and practices. This article presents a systematic mapping of proposals which have been adopting Linked Data to support education, and, based on analysis of these proposals, we discuss the tools, vocabularies, and datasets being used, providing a research landscape of the area. We also present challenges and trends which can foster future research in this area.