Bed-parallel slip (BPS) is an underappreciated yet structurally significant mechanism for accommodating extensional deformation in layered sedimentary basins. This study demonstrates that bed-parallel slip (BPS) is a fundamental process in the extensional rift margin of the northwestern Red Sea, significantly influencing the evolution of fault architecture, strain partitioning, and rift basin evolution. BPS surfaces are persistently localized within mechanically weak intervals—chief among them evaporites, mudstones, and intraformational conglomerates—where low shear strength and fluid activity facilitate slip along bedding planes. These surfaces contribute to the segmentation and displacement of major normal faults, resulting in complex, multi-level fault architectures, as revealed by both outcrop and seismic data. The relative timing between BPS and steep, dip-slip faults is highly variable, with BPS capable of predating, postdating, or developing coeval with faulting, depending on the local structural and stratigraphic context. Field evidence documents a suite of associated deformation features, including extensional veins, breccias, and forced folds, which collectively record the dynamic interplay between gravitational sliding and faulting. Large lateral offsets along BPS surfaces, comparable to those reported from other extensional basins, confirm the regional significance of this process. Overall, the results highlight that BPS, driven by gravitational sliding on weak, rotated beds, fundamentally modifies the architecture, connectivity, and evolution of fault zones in layered rift systems, with broad implications for understanding strain accommodation, fault reactivation, and fluid migration in continental margins worldwide.