In the current communicational scenario, transformed by technological and digital advances, media literacy is considered a crucial competence for active and informed participation in society. In this context, the main objective of this study was to assess the media literacy competences of 416 students of the 4th, 6th, and 9th grades in Portugal, identifying training needs and presenting suggestions for intervention. A non-experimental quantitative methodology was used, and the participants completed a self-response questionnaire. The results indicate that the three grades studied have a transversal need regarding the use of media, the production of media content, and participation in society through the media, and also regarding the analysis, understanding, and assessment of media content. We confirm the importance of media education in the development of media literacy and present some intervention suggestions for the promotion of these competences in the school context, namely the reinforcement of some curricular content, the use of guiding documents, and the development of critical thinking. We emphasize the importance of training teachers and parents on the subject, and finally, we also emphasize the importance of deconstructing the belief that digital natives have natural competences in this regard and therefore do not need training in this area.