A vehicle lower section structure that includes: a floor panel; a dash panel partitioning an engine compartment from a vehicle cabin; a front side member that extends in a vehicle body front-rear direction on a vehicle body front side of the dash panel, and that is disposed along a lower face of the floor panel on a vehicle body rear side of the dash panel; a rocker extending in the vehicle body front-rear direction; a torque box that extends in the vehicle width direction, that is joined to the lower face of the floor panel between the front side member and the rocker in bottom face view, and that forms a closed cross-section profile together with the floor panel; and a bulkhead running along the vehicle body front-rear direction inside the torque box and sectioning the inside of the torque box in the vehicle width direction.