A drive assist system includes: a movable body (20) in which drive assist is performed by an assist device (40, 50, 60) and which includes a movable body holding unit (23); an external holding unit (14) located outside the movable body (20); and a controller (22) configured to determine whether or not an operation position where the assist device (40, 50, 60) operates is related to the operation of the assist device (40, 50, 60), select the external holding unit (14) as a unit in which the operation result of the assist device (40, 50, 60) is to be held when it is determined that the operation position is not related to the operation of the assist device (40, 50, 60), and select the movable body holding unit (23) as the unit in which the operation result of the assist device (40, 50, 60) is to be held when it is determined that the operation position is related to the operation of the assist device (40, 50, 60).