Building on systems theory and its applications in tourism management, we introduce the natural science evolutionary 'endosymbiosis theory' to interpret the inter-dependencies of youth employment and tourism. Tourism organisations are located within a tourism industry or a sub-system, which in turn is bounded within a broader socio-economic ecosystem. We mobilise three classifications of symbiosis -mutualism, commensalism and parasitism to: a) test the analytic utility of this theoretical approach as a means to unpack the young worker and tourism employment relationships, and b) unify hitherto disparate literatures on the youth-tourism employment relationship. In particular, we model the explanatory value of endosymbiosis theory, navigating the ethicalities and moralities of the social sciences, in progressing our understanding of the tourism-young worker intersection.