Background and Objectives Great-grandparenthood brings a new internal dynamic to intergenerational relationships in which contact between four generations is now the norm. In this scoping review, we sought to identify the roles of great-grandparents and what those roles entail. Research Design and Methods We performed a review using PRISMA-ScR to identify peer-reviewed studies investigating the roles of great-grandparents. The reviewed articles were selected from four databases. The article selection conditions were met by 23 studies that used quantitative or qualitative methods. The studies had to be published in English; the selected publications spanned eight countries. Results The scoping review covers a collection qualitative and quantitative research with different types of respondents (great-grandchild, grandparents, great-grandparents, etc.). An important element was a statement on great-grandparenting from at least one of the four generations. We selected 23 articles from an initial selection of 176 studies. The studies were heterogeneous in conceptual frameworks, collection methods, and interview conduct, with qualitative methods predominating over quantitative methods. Discussion and Implications Based on research on great-grandparenting, the roles of great-grandparents can be categorized as continuing, insignificant, or significant. Each role category has a specific function and each represents a different meaning for the great-grandparents within the family. Several factors and constraints frame the great-grandparent roles. Based on the research results, some characteristics are shared by all role categories despite the dividing elements.