Reading literacy has been considered one of the essential vital competencies in modern society and has thus gained increasing attention in research. With both qualitative and quantitative research methods, this study aimed to investigate the overall picture in this research field and investigate the role of reading motivation and online reading activities and how online reading literacy was assessed. The top ten organizations, countries with the highest publications, author keywords, all keywords, cited references, cited sources, and cited authors were visualized via VOSviewer clustering and counting techniques. Reading motivation, online reading activities, and digital reading literacy assessment tests were also explored through the visualization citation network in CitNetExplorer. In conjunction with the citation network, 13 peer-reviewed articles were selected for further analysis based on the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P). The results show that reading motivation played an essential role in reading literacy achievement in formal schooling, while online reading activities could both positively and negatively affect digital reading literacy due to their multifaceted nature. The digital reading literacy assessment tests vary across the world. Implications for widely investigating adults and L2 reading literacy and relevant support or interventional measures to boost reading literacy were also discussed.