Prior to devolution, Scotland, Wales, and Northern Ireland each had their own autonomous development organisations to undertake and promote regional economic planning and development within their respective territories. These operated within a national UK regional policy framework. An expectation of devolution was that the development organisations would continue to evolve in different ways according to the prevailing and anticipated economic conditions and differentiated needs and priorities of the regional economies. Indeed, the model was further extended. In England, for example, regional development agencies were established as an integral part of the new intended Regional Assembly infrastructure—providing important economic development delivery functions to the new political bodies. In general terms, a more effective integration of planning, infrastructure provision, business development and investment, and economic development was anticipated at the regional level. This was held as an effective means of contributing to national economic growth and competitiveness objectives: themselves key and pivotal rationales for political devolution. On the basis of benchmarking exercises and academic and policy literature we review and analyse the significant changes that have taken place in the institutions which have been generated across the UK since the late 1990s, presenting and contrasting each nation’s and region’s experiences with an appreciation of their specific powers and resources.