As viewed from a side, an output shaft is disposed rearward of a crankshaft, and an odd-numbered stage shaft and an even-numbered stage shaft are disposed rearward of the crankshaft. Moreover, the odd-numbered stage shaft is provided on a side opposite to the even-numbered stage shaft relative to a line connecting the crankshaft and the output shaft, and a shift drum is disposed on a side opposite to the output shaft relative to a line connecting the odd-numbered stage shaft and the even-numbered stage shaft. This structure reduces dimensions of the power unit for the saddled vehicle.