This monograph reviews the evolving and extensive literature on immigrant entrepreneurship since the 1970s. It is based on a detailed analysis of 118 key articles published in entrepreneurship, economics, management, and sociology journals. Our review is structured into three main sections to consider research into immigrants' motives for entrepreneurship, their business strategies, and their performance and impact. Within each section, we review research focusing on immigrant entrepreneurs' personal characteristics, their ethnic community networks, and the external eco-system. We consider studies of transnational entrepreneurship separately in each section to capture the evolution of research from studies of immigrant entrepreneurs operating in ethnic enclaves to those of entrepreneurs operating in transnational landscapes. In addition, we review research on the diversity among immigrant entrepreneurs, and issues of succession and gender. We outline research gaps and methodological challenges in immigrant entrepreneurship research. Finally, we suggest areas of future research. By including studies of transnational entrepreneurs, we extend the prior literature on immigrant entrepreneurs to highlight the diversity among them and the significance of their international activities. We believe this monograph will be of value to scholars of immigrant entrepreneurship as well as those at the crossroads of immigrant entrepreneurship, international entrepreneurship, and international business.