Multi-level issues and multiple levels of analysis are important in leadership research. In this chapter, the authors identify and explain multi-level issues particularly relevant for leadership theory and methods, including the primary levels in organizations; alternative views of each level; level-specific, emergent, and cross-level relationships; and time, fallacies, and analytics for multiple levels of analysis. They then explore in greater depth the level of analysis that to date has been the most neglected and misunderstood in leadership research – dyads. In doing so, they highlight different dyadic conceptualizations, including dependencies within and between dyads, independent and dependent dyads, and nested and cross-classified dyads; and highlight three methodological approaches for dyadic leadership research – actor–partner interdependence model, random coefficient modeling, and within and between analysis – with discussion of their similarities and differences. Finally, some recommendations for multi-level theory and methods in general, and dyadic research specifically, in the leadership realm are offered.