A vehicle-body lower structure includes: a side sill; and a cross member, wherein the side sill includes a side sill outer and a side sill inner, a bulk having a shape corresponding to the cross member is provided on the opposite side of the side sill inner from the cross member in a closed-section space formed by the side sill outer and the side sill inner, and the bulk includes a front wall portion, a rear wall portion placed behind the front wall portion in the vehicle-body front-rear direction, and a connecting wall portion connecting the front wall portion and the rear wall portion, the front wall portion and the connecting wall portion forming a first edge line extending in the vehicle width direction, and the rear wall portion and the connecting wall, portion forming a second edge line extending in the vehicle width direction.