New towns were a cornerstone of the post-war British planning system. They have been both praised and derided, but are, in reality, little understood. Research has mainly focused on the experience of a few iconic examples, such as Cumbernauld and Milton Keynes; other new towns, especially in the north-west of England, have been relatively neglected. This means that there is a lack of understanding of how new towns were designed in very different contexts, and of how their often experimental, modernist designs were implemented over time. Recent proposals to establish new development corporations in the Oxford-Cambridge Arc mean that an examination of new town design and implementation is more timely than ever.This dissertation responds by assessing the design and implementation of Skelmersdale New Town, near Liverpool, a little-studied example designated in the early 1960s and built out by its development corporation until 1985. The dissertation begins by assessing the town’s design, demonstrating how it embodied the priorities of its architect-planner, Hugh Wilson. These priorities – full automobility, urban character and compactness – reflected the context of early 1960s modernism and responded to criticism of earlier new towns, but took limited account of the local context.The dissertation then discusses Skelmersdale’s implementation, arguing that this brought to the fore the development corporation’s dependence on central government. The development corporation was able to provide the planned-for housing, industrial premises and road network, as these were government priorities in the early years of implementation. However, it struggled to achieve the affluent urban character planned in the overambitious, sometimes contradictory design. Skelmersdale’s experience reveals that while comprehensive modernist planning was a powerful tool in creating housing and infrastructure, it was limited by its inability to fully predict future economic and political conditions.