In a driving assist device, an electronic control unit is configured to determine whether a target position is able to be decided from a predetermined object indicating that a vehicle needs to be decelerated, when recognizing the predetermined object, to perform a first assist by which the vehicle is decelerated at a first deceleration that is changed based on a brake operation by a driver, when determining that the target position is not able to be decided, and to perform a second assist by which the vehicle is decelerated at a second deceleration that is equal to or higher than a predetermined deceleration necessary to decelerate the vehicle to the target velocity before the vehicle reaches the target position decided from the predetermined object, when determining that the target position is able to be decided.