An oil supply device for a vehicle includes an oil pump driven by a rotation of an internal combustion engine, a hydraulic actuator to which oil is supplied from the oil pump, an engine lubricating system to which the oil is supplied from the oil pump, an oil supply adjusting valve adjusting a supply condition of the oil from the oil pump to the hydraulic actuator and the engine lubricating system, a first oil supply passage supplying the oil from the oil pump to the hydraulic actuator, and a second oil supply passage supplying the oil from the oil pump to the engine lubricating system, wherein the oil supply adjusting valve consistently distributes the oil to the first oil supply passage and the second oil supply passage.