The emergence of educational technologies has spurred research interest in exploring effective ways to enhance human learning in digital environments. Social Learning Theory (SLT), as a crucial theory that offers a conceptual framework for understanding the role of human agency in learning, can shed light on the underlying mechanisms of learners' social learning behaviors, such as engagement and collaboration, in online learning contexts. However, there is a gap in the literature regarding reviews of online learning studies grounded in SLT. Therefore, this systematic review aims to examine SLT-related online learning studies to investigate how SLT contribute to the understanding of the technology integration in human learning. The review includes two descriptive research questions on research trends and implementation categories, alongside two qualitative research questions investigating the significance of SLT concepts in understanding social learning online implementations. The PRISMA method was employed to select and analyze 60 studies. Deductive content analysis revealed two major educational affordances of social networking sites that result in social learning experiences: collaborative interaction and observational participation.