This chapter focuses on engagement in business-to-business contexts. It analyzes a number of specific properties of business markets (e.g. the derived character of demand or formalization / rationality of exchange) and discusses their implications for the phenomenon of customer engagement. Furthermore, the authors argue that the concept of customer engagement should be extended to partner engagement in order to reflect the complexity and network character of value chains in business markets. Finally, the authors develop a typology of partner engagement behaviors in business markets and discuss differences with respect to the level of engagement (organizational vs. individual), underlying relational factors as well as special cases. Based on the analysis, the authors derive specific implications for B2B managers and provide avenues for future research in the domain of partner engagement.