An object is to restrain increase in size of a drive unit while enhancing booster pump functions, in the drive unit which includes an engine main body unit and a transmission unit which are lubricated by shared oil. A drive unit (11) for a straddled vehicle includes an engine main body unit (20), a transmission unit (21), and a shared lubrication oil supply mechanism (22). The shared lubrication oil supply mechanism (22) includes a first booster pump (80A) which pressurizes the shared lubrication oil lubricating both the engine main body unit (20) and the transmission unit (21) and a second booster pump (80B) which pressurizes at least part of the shared lubrication oil which has been pressurized by the first booster pump (80A) and which is in a positive pressure condition.