Ontario–Quebec relations have flourished in recent years. Environmental and economic agreements have proliferated (infrastructure, trade, investment, labour mobility) and a total of three joint provincial-cabinet meetings were held between 2008, 2009, and 2010. These closer ties provide a good opportunity to reflect on the provinces’ shared destiny. Our objective in this book is to contribute to the body of knowledge on Ontario–Quebec relations and spark renewed interest among researchers on this topic. Our methodology combines historical and comparative approaches. The first part focuses specifically on the origin and current state of relations between the two provinces. It offers a “big picture” view of interprovincial relations from a number of perspectives (political, economic, social, and public policy). The second part compares key public policy issues in the provinces in a wide range of fields. The analyses provided illustrate the similarities and differences between Ontario and Quebec, and provide a better understanding of the issues and policies that affect Ontario–Quebec relations.