Zebrafish are an established model organism in developmental and behavioral neuroscience, also recently emerging as an excellent model to study social behavior. Zebrafish are highly social, forming groups (shoals) with structured social relationships, dominance hierarchies and overt territoriality. Moreover, social behavior in zebrafish exhibits considerable plasticity both within- (i.e., as a context-dependent behavior) and between individuals (e.g., sex-differences, personality and coping styles) of the same strain, as well as between strains. This richness and plasticity of social behavior, together with the genetic tools available to visualize and manipulate neural circuits in zebrafish places it in the forefront of studying the neurobiological mechanisms underlying complex social behavior. Here, we review the cognitive abilities involved in social behavior, as well as the different functional classes of social behavior present in zebrafish and their variation. We also highlight recent ground-breaking methodological developments in the field, including automated image-based tracking and classification of behavior coupled with video-animated social stimuli, which collectively foster the development of future high-throughput screens of zebrafish social phenotypes.