Salt diapirism is a distinctive feature of the Mesozoic–Cenozoic basins of western Iberia and has been associated with petroleum seeps and shows since the dawn of petroleum exploration in this province. Interpretation of two-dimensional (2-D) and three-dimensional (3-D) seismic data sets in the Lusitanian Basin provides insight into the evolution of some of the main subbasins, resulting in new evidence that supports the onset of Hettangian salt movement right after salt deposition, as well as helping to characterize other salt-related features due to extension and shortening, such as salt pillows, walls, and megaflaps. In the offshore Peniche Basin, 2-D and 3-D seismic interpretation confirms the widespread presence of Triassic–Aptian rift-related units that developed mostly on half grabens and grabens, followed by thick Upper Cretaceous postrift and Cenozoic cover. The 3-D seismic data acquired over the Northern Peniche Basin reveals multiple styles of mature diapiric structures, the impact of salt withdrawal on the creation of primary and secondary minibasins, as well as the influence of diapirism in Early Cretaceous deep-water channel systems by using spectral decomposition. Contrastingly, 2-D interpretation in the southern sector of the Peniche Basin reveals the impact of the Cenozoic inversion in the present-day architecture of the basin, mostly characterized by thick-skinned tectonics and mild salt diapirism. The interpretation of existing seismic data sets over the Lusitanian and Peniche Basins offered new insights into the role of salt in the tectono-sedimentary evolution, which may influence future petroleum exploration campaigns as well as sweet spot geocharacterization for energy resource storage.