The mobile phone has become the preferred means of communication, especially among young people, and there are many teachers who are committed to introducing it as a resource in their classrooms. Therefore, the objective of this work was to describe the educational uses of WhatsApp. The methodology was a systematic review of published work on the subject, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and similar phases in the process. The sample was made up of 192 papers, which shows the large amount of research that has gone into the subject. WhatsApp’s educational use comes from the creation of groups—students alone or including the teacher. It is applied in both formal and informal education in all educational stages and in numerous subjects. It is also related to improvements in active learning, decision-making, and motivation, in addition to skills related to efficiency, planning, and time organization. Although the application was not designed for the educational environment, its advantages have shown it to be an adequate educational and support resource in teaching and learning at all educational stages.