This chapter explores knowledge and innovation through the lens of economic geography, focusing on the U.S. and international case studies. The chapter presents the nuances, in particular, the channels of learning, transfer, and management of knowledge. It delves into terms such as epistemic community and tacit knowledge. The dynamic flow from knowledge sharing into entrepreneurship and innovation in the industry cluster setting is also discussed. The chapter presents several case studies of industry clusters, including international examples of manufacturing and high-technology clusters, as well as cultural districts. The chapter concludes by exploring the roles of industry clusters in developmental pathways such as modernism and economic and human development.