Radar images obtained from the Magellan mapping mission reveal that much of the surface of Venus has undergone tectonic deformation. Though normal and thrust faults are common, there has been little evidence of discrete, large-offset strike-slip faults on Venus. We present a clear example of large-scale strike-slip faulting in Lavinia Planitia, Venus. Our observations of the spatial and temporal relationships between the Molpadia Linea deformation belt and an associated fracture system indicate that the fractures were formed as the result of strike-slip faulting localized along the belt. Global tectonism on Venus is dominated by vertical deformation; we attribute this example of horizontal deformation to a reorientation of the regional stress field associated with mantle downwelling.