In 1979, a New York Times reporter suggested that Saudi Arabia’s new industrial cities might prove “a huge white elephant… forever dependent on foreign labourers.” Four decades later, Yanbu Industrial City stands as a refutation of that verdict — one of the Kingdom’s most strategically important energy and manufacturing hubs, and a textbook case study in state-directed industrial urbanisation. This article traces Yanbu’s transformation from a small fishing port into a major petrochemical and industrial complex under the Royal Commission for Jubail and Yanbu, examining the planning principles, institutional arrangements, and sequenced investment decisions that underpinned its success. The analysis draws implications for contemporary planned industrial city development and Vision 2030’s diversification agenda.