A vehicle lower portion structure includes side rails respectively disposed on right and left sides and extending along a longitudinal direction, and further includes a cab mount bracket fixed to an outer side of each of the side rails in a vehicle width direction, in which a vehicle body is secured above the cab mount bracket. The vehicle lower portion structure further includes a connector disposed on an upper side of the cab mount bracket and configured to connect the cab mount bracket to the vehicle body, in which at least one of a wire harness and a brake pipe is arranged outside of at least one of the side rails in the vehicle width direction in a region located inward of the connector in the vehicle width direction and upward of the cab mount bracket.