Providing a concise working definition of social capital, this conceptual paper analyses why social capital is important for learning and economic development, why it has a regional dimension, and how it is created. It argues that with the rise of the Knowledge Economy, social capital is becoming valuable because it organizes markets, lowering business firms’ costs of coordinating and allowing them to flexibly connect and reconnect. Thus, it serves as a social framework for localized learning in both breadth and depth.