This chapter provides a brief overview of how cultural diversity has been addressed by cultural economics. It first provides a definition based on the Stirling model. It then differentiates between two types of cultural diversity: identities and expressions. Researches on the former usually address its impact, from a management point of view. It is found that the diversity of cultural identity has mostly a positive impact on team efficiency. Researches on the diversity of cultural expressions have mainly focused initially on the ambiguous links between the diversity of cultural expressions and market concentration, notably with an opposition between the respective effects of economies of scale and economies of scope. The rise of online platforms relies on the same ambiguities and can be approached by opposing superstar theory and the long tail. There is also a growing literature on the impact of algorithms (such as recommendation systems) on the diversity of cultural expressions, which deserves more scrutiny by cultural economists in the coming years.