Agglomeration, Industrial Districts and Industry Clusters: Trends of the 21st Century Literature reviews the early work of 21st Century scholarship on agglomerations, industrial districts and industry clusters and explores the context to the prominent themes that emerged between 2000 and 2015. A specific objective of this monograph is to highlight the role of entrepreneurs in the literature. After an introduction, this monograph examines the potential of and for industry concentration. One of the factors identified in these articles as important for driving industry concentration is the entrepreneurship that operates in the region. Therefore, Section 3 offers a review of the literature that focuses on entrepreneurship and industry concentration. Section 4 examines the concentration of firms, buyers and suppliers within a region, which has offered opportunity for scholars to examine networks, relationships and industry concentration. Next, the author presents the research around why firms agglomerate and the noted benefit to firms that operate in networks, knowledge and industry concentration that was another theme that emerged in the 21st century literature. Whereas much of the industry focus of empirical studies published in the 20th century focused on manufacturing firms or those in the fashion industry, the 21st century noted a shift in industry focus with considerable discussion on creative and knowledge based industries; Section 6 focuses on the topics around creative and high technology industries and industry concentration. Each section concludes with thoughts on the scholarship that is needed to continue advancing the important topics on industry concentration. A summary of these thoughts is provided in Section 7.