Fuel tank structure

A partitioning plate, that is positioned between a jet pump and a main suction, is set within a reserve cup of a fuel tank, so as to separate an interior of the reserve cup into a fuel feed-out chamber in which the main suction is disposed, and a fuel introducing chamber in which the jet pump is disposed. The partitioning plate is disposed at an incline with respect to a vehicle longitudinal direction. In cases in which acceleration in any of a forward direction, a rearward direction, a leftward direction and a rightward direction of a vehicle acts on fuel within the reserve cup, some of fuel within the fuel introducing chamber flows into the fuel feed-out chamber. A fuel tank structure is provided that can reliably ensure fuel within the fuel feed-out chamber in a case in which acceleration arises at fuel within a fuel accommodating portion.