A straddled vehicle, comprising: a fuel tank; a head pipe; a down frame portion extending downward from the head pipe; a rear frame portion disposed rearward of a front end of the down frame portion, the rear frame portion including a lower frame portion (16,17) and a seat frame portion (18,19), the lower frame portion (16,17) extending rearward from the down frame portion at a lower position than the head pipe, the seat frame portion (18,19) extending rearward and upward from the lower frame portion (16,17); a seat for a rider, at least a portion of the seat being disposed over the seat frame portion (18,19); and a coupling frame portion extending in a vehicle back-and-forth direction at a higher position than the lower frame portion (16,17), the coupling frame portion coupling the down frame portion and the rear frame portion, wherein the coupling frame portion is made of sheet metal, and the coupling frame portion includes a transverse plate portion and a longitudinal plate portion (42,43), the transverse plate portion extending in a vehicle width direction, the longitudinal plate portion (42,43) extending in an up-and-down direction wherein a left floor step portion is disposed leftward of the head pipe and in a lower position than the coupling frame portion, at least a portion of the left floor step portion being located between a rear end of the head pipe and a front end of the seat in the vehicle back-and-forth direction; a right floor step portion is disposed rightward of the head pipe and in a lower position than the coupling frame portion, at least a portion of the right floor step portion being located between the rear end of the head pipe and the front end of the seat in the vehicle back-and-forth direction; a center tunnel portion disposed between the left floor step portion and the right floor step portion in the vehicle width direction, the center tunnel portion having a cross-section made in an upwardly bulging convex shape, the center tunnel portion extending in the vehicle back-and-forth direction, characterized in that the fuel tank is disposed under the coupling frame portion within the center tunnel portion, wherein the coupling frame portion is disposed within the center tunnel portion, and a vehicle width directional dimension of the coupling frame portion is smaller than a vehicle width directional dimension of the fuel tank in a vehicle plan view. a fuel tank; a head pipe; a down frame portion extending downward from the head pipe; a rear frame portion disposed rearward of a front end of the down frame portion, the rear frame portion including a lower frame portion (16,17) and a seat frame portion (18,19), the lower frame portion (16,17) extending rearward from the down frame portion at a lower position than the head pipe, the seat frame portion (18,19) extending rearward and upward from the lower frame portion (16,17); a seat for a rider, at least a portion of the seat being disposed over the seat frame portion (18,19); and a coupling frame portion extending in a vehicle back-and-forth direction at a higher position than the lower frame portion (16,17), the coupling frame portion coupling the down frame portion and the rear frame portion, wherein the coupling frame portion is made of sheet metal, and the coupling frame portion includes a transverse plate portion and a longitudinal plate portion (42,43), the transverse plate portion extending in a vehicle width direction, the longitudinal plate portion (42,43) extending in an up-and-down direction wherein a left floor step portion is disposed leftward of the head pipe and in a lower position than the coupling frame portion, at least a portion of the left floor step portion being located between a rear end of the head pipe and a front end of the seat in the vehicle back-and-forth direction; a right floor step portion is disposed rightward of the head pipe and in a lower position than the coupling frame portion, at least a portion of the right floor step portion being located between the rear end of the head pipe and the front end of the seat in the vehicle back-and-forth direction; a center tunnel portion disposed between the left floor step portion and the right floor step portion in the vehicle width direction, the center tunnel portion having a cross-section made in an upwardly bulging convex shape, the center tunnel portion extending in the vehicle back-and-forth direction, characterized in that the fuel tank is disposed under the coupling frame portion within the center tunnel portion, wherein the coupling frame portion is disposed within the center tunnel portion, and a vehicle width directional dimension of the coupling frame portion is smaller than a vehicle width directional dimension of the fuel tank in a vehicle plan view.