Under the requirements of modernized spatial governance and the national strategy for the integrated development of the Yangtze River Delta, the Shanghai Metropolitan Area has taken the lead in exploring collaborative governance in regional spatial planning, which aims to promote spatially coordinated governance and high-quality integrated development in metropolitan areas. This exploration focuses on the preparation and organizational innovation in regional planning, the combination of top and bottom organizational approaches, the importance of equal consultation during the planning process, the establishment of an open platform in the positioning of the planning, and the need for joint determination in planning approval. This exploration also discusses the innovative implementation of spatial planning cooperation through eight systematic actions and five space sector actions and defines the implementation focus through the immediate plan of action at the implementation level. The exploration of the “Spatial Cooperative Plan of the Greater Shanghai Metropolitan Area” demonstrates that the process and result of planning are equally important. Achieving consensus through plan making and fostering synergies through plan implementation are feasible paths for efficient collaborative governance in the Shanghai Metropolitan Area and other metropolitan areas in China.