Abstract: A dynamic seat leveling device for a riding lawnmower or tractor has a virtual rotational point located below the leveling device itself. When operated on hilly terrain, such an arrangement accomplishes three objectives: 1) the operator remains level; 2) the operator's center of gravity remains centered directly above a critical balance point which is at ground level, midway between the right and left wheels; and 3) the operator remains at a constant elevation. Keeping the operator at a constant elevation, as the leveling device shifts from one side to the other, minimizes the power that would otherwise be needed to repeatedly raise and lower the operator as the tractor tilts from left to right. Minimizing the power required allows the use of a compact leveling drive that fits between the seat and frame of the tractor.