A vehicle frame structure includes a side sill having an internal space partitioned by a vertical rib and a horizontal rib intersecting the vertical rib. The vertical rib separates the side sill into an outer lateral portion and an inner lateral portion. The inner lateral side sill portion includes a cutout extending vertically therethrough. A pillar has an internal space partitioned by a longitudinally extending first rib and a laterally extending second rib intersecting the first rib. The first rib separates the pillar into an outer lateral portion and an inner lateral portion. The inner lateral pillar portion is disposed through and secured in the cutout of the portion, and an axial end face of the outer lateral pillar portion is in abutment with the outer lateral side sill portion. The side sill and the pillar are welded to each other along an interface between the two components.