According to the UN Sustainable Development Goals, tourism's social impacts should stretch beyond ensuring greater equality and opportunity, and should also foster peaceful societies. This chapter explores the impact tourism can have on peace, exposing arguments for and against the notion that tourism is the world's "peace industry". Reflecting on a divided academic debate over this proposition, we suggest that a problem in our ability to evaluate tourism's impact on peace is the existence of, at best conflicting, at worst absent, conceptualizations of peace amongst tourism scholars. Using literature from relevant disciplines, such as peace studies, we explore these different conceptualizations of peace and suggest that tourism scholars need to be far clearer in our understanding of peace. This, in turn, will enable us to more clearly evaluate tourism's impact on peace.