A straddled vehicle comprising: a vehicle body frame ; an engine pivotably supported by the vehicle body frame ; a storage box disposed above the engine in a vehicle up-and-down direction; a seat disposed above the storage box in the vehicle up-and-down direction; an intake pathway portion disposed below the storage box in the vehicle up-and-down direction, the intake pathway portion being connected to the engine ; and a tensioner disposed between the intake pathway portion and the engine in the vehicle up-and-down direction, the tensioner being attached to the engine , wherein the tensioner includes a first accommodation portion disposed outside the engine , the first accommodation portion being attached to the engine , a second accommodation portion disposed inside the engine , the second accommodation portion being connected to the first accommodation portion , characterized in that the tensioner further includes a first shaft at least in part disposed inside the first accommodation portion , the first shaft including a first threaded portion , a second shaft at least in part disposed inside the second accommodation portion , the second shaft being moved in an axis direction (Ax2) of the tensioner in accordance with rotation of the first shaft , the second shaft including a second threaded portion and a distal end , the second threaded portion being screwed with the first threaded portion , the distal end protruding from the second accommodation portion into the engine , and a spring urging the first shaft to rotate the first shaft , the tensioner at least in part overlaps with the intake pathway portion as seen in a vehicle plan view, and the spring is disposed inside the first accommodation portion and the second accommodation portion . a vehicle body frame ; an engine pivotably supported by the vehicle body frame ; a storage box disposed above the engine in a vehicle up-and-down direction; a seat disposed above the storage box in the vehicle up-and-down direction; an intake pathway portion disposed below the storage box in the vehicle up-and-down direction, the intake pathway portion being connected to the engine ; and a tensioner disposed between the intake pathway portion and the engine in the vehicle up-and-down direction, the tensioner being attached to the engine , wherein the tensioner includes a first accommodation portion disposed outside the engine , the first accommodation portion being attached to the engine , a second accommodation portion disposed inside the engine , the second accommodation portion being connected to the first accommodation portion , characterized in that the tensioner further includes a first shaft at least in part disposed inside the first accommodation portion , the first shaft including a first threaded portion , a second shaft at least in part disposed inside the second accommodation portion , the second shaft being moved in an axis direction (Ax2) of the tensioner in accordance with rotation of the first shaft , the second shaft including a second threaded portion and a distal end , the second threaded portion being screwed with the first threaded portion , the distal end protruding from the second accommodation portion into the engine , and a spring urging the first shaft to rotate the first shaft , the tensioner at least in part overlaps with the intake pathway portion as seen in a vehicle plan view, and the spring is disposed inside the first accommodation portion and the second accommodation portion . <EOS>