A vehicle body includes a floor assembly having a center floor and a rear floor, a pair of side structures connected to both sides of the floor assembly, and a pair of side sills connected to both side edges of the floor assembly, wherein each side sill includes an inner side sill facing an interior of the vehicle body, an outer side sill facing an exterior of the vehicle body, and first and second side sill reinforcements disposed between the inner side sill and the outer side sill, and wherein a rear end portion of the first side sill reinforcement overlaps a front end portion of the second side sill reinforcement.