A vehicle lower section structure including: a left and right pair of vehicle body frame members; a lower extension section joined to each of the left and right pair of vehicle body frame members, the lower extension section including: a front lower extension section extending toward a vehicle lower side, and a rear lower extension section disposed at a vehicle rear side of the front lower extension section and extending toward the vehicle lower side; and a front-rear direction extension section that bridges the vehicle front-rear direction between the front lower extension section and the rear lower extension section, the front-rear direction extension section provided with a lower arm support section that a lower arm is attached to pivotably substantially a vehicle vertical direction, and the front-rear direction extension section being joined to the rear lower extension section at the vehicle rear side of the lower arm support section.