The development of new educational environments based on the use of ICT has enabled the possibility to improve access and involvement for students with disabilities at the university level. Hence, this systematic review attempts to synthesise the main findings of previous interventions aimed to promote the inclusion of these students in Online Higher Education, as well as to analyse their contribution on the students' academic success, by considering the principles of both Universal Instructional Design and Universal Design for Learning. A systematic search was conducted in four databases (WOS, Scopus, ERIC, and ProQuest) following the PRISMA-P statement. This search yielded 15 articles according to the defined criteria. Four thematic categories were identified throughout a thematic synthesis: Accessibility, support, socialisation, and academic success. The findings show that both accessibility and support are important factors for promoting the disabled students' academic success in Online Higher Education but also highlight the need to apply the Universal Design in the whole system. Furthermore, the issues of academic support, inclusive pedagogical practices, and socialisation should be deeply analysed to inquire about their contribution to the students with disabilities' academic success. Lastly, the limitations of this study and future implication for research are discussed.