A vehicle underbody structure includes a catalyst disposed in a front portion of an exhaust pipe; a cover member for covering the catalyst from above; and a heat insulator disposed inside a tunnel portion behind the catalyst and configured to cover the exhaust pipe from above. The heat insulator is disposed away from the tunnel portion by a predetermined gap in an up-down direction. A front portion of the heat insulator and a rear portion of the cover member are disposed in such a way as to overlap each other. A front end of the heat insulator is disposed on the upper side with respect to a rear end of the cover member.