The antecedents and outcomes of individual-level flow are well documented in a large body of literature. However, flow does not only occur in isolation – quite to the contrary, recent evidence suggests that social interaction can facilitate the experience of flow. Therefore, we propose a taxonomy, which distinguishes five different flow states according to two global factors: interactional synchrony and self-other overlap. Solitary flow bears all characteristics developed by Csikszentmihalyi. Co-active flow is facilitated or hampered by the presence of other people. Private interactive flow emerges on the grounds of a minimal unidirectional interaction with more passive others; only the active subject is in flow. In shared interactive flow, a fully synchronized activity between group members takes place and all group members are in flow. In group flow, all members reach a level of complete self-other overlap with the group, which leads to a collective experience of flow on the group-level. In addition to differences and commonalities of the different types of flow, suggestions for how to induce and study social flow are discussed.