Saddle-riding vehicle

In a saddle-riding vehicle, a separation device (60) is disposed in a blow-by gas path. The separation device (60) is positioned laterally on one side of a vehicle center line extended in a back-and-forth direction. At least a portion of an oil cooler (50) is positioned on the same side as the separation device (60) with respect to the vehicle center line. In a side view, at least a portion of the separation device (60) is disposed in such a position that at least a portion of the separation device (60) is overlapped with an engine (3) in the back-and-forth direction. In a side view, at least a portion of the separation device (60) is positioned above the engine (3).