A vehicle travel support device is capable of properly controlling the operation of a steering device and the like from the viewpoint of supporting the travel of a vehicle stably even in a situation where a travel area is inappropriately demarcated by right and left lane marks at both sides. A virtual travel area can be set as a travel area when a first condition is satisfied, that is, when the separation between the right and the left lane marks in width direction of a road increases to an inappropriate extent from the viewpoint of demarcating the travel area because the separation therebetween gradually increases as the distance from the vehicle increases. The operation of a steering device and the like is controlled such that the vehicle will not depart from the virtual travel area set as the travel area.