A driving assistance device for a vehicle, comprising: a detection unit that detects a vicinity condition of the vehicle and a running condition of the vehicle; a driving control unit that, on the basis of detection results from the detection unit, controls at least a portion of driving operations of the vehicle and controls autonomous driving that is capable of an overtaking maneuver to overtake a vehicle in front; an operation unit that implements an operation to change a specified speed during the autonomous driving; and a control unit that, after the operation to change the specified speed is implemented by the operation unit in a state during autonomous driving in which a vehicle in front is detected by the detection unit, controls the driving control unit so as to carry out the overtaking maneuver.