Dyslexia can have an impact on online learning outcomes. However, few studies have examined the association between dyslexia and online learning effectiveness. This systematic review focused on the effects of dyslexia on online learning effectiveness to conduct research in three major categories: analysis of impact, analysis of dyslexia on online learning, and analysis of interventions. A screening of two bibliographic databases identified 37 articles that met the inclusion criteria. The study determined that dyslexic learners are uncomforted with online learning and suffer from frustrated self-confidence and decreased academic performance in the learning process. It even affects the learners' evaluation of themselves and causes a decrease in self-efficacy. Among these, research on influencing factors can be divided into two dimensions: internal and external factors. Dyslexic learners are influenced by both the type of dyslexia and their psychological characteristics, as well as by teachers, teaching strategies, online educational environments, and educational media. These influences provide intervention strategies, such as developing customized online learning systems for dyslexic learners and exploring interventions in telerehabilitation medicine. However, no intervention strategies involve adjustments to the internal psychology of dyslexic learners and external support systems. Therefore, more research is needed to explore the differential impact of dyslexia on online learning and to understand the factors that produce this impact to provide a theoretical basis and direction for the generation of instructional strategies for dyslexics and the adaptation of online learning for dyslexics.