An attachable canopy for a riding lawnmower for providing a shading mechanism for a user seated on such a lawnmower includes a harness formed from a wrap around elongated strap that has a first end that is connectable to a second end, a frame which includes two elongated rods whose proximal ends are connected to opposite sides of the harness, and a canopy which is connected to the distal ends of the rods. The harness is adjustable so as to be attachable to either the seat or seat back of a riding lawnmower. In this regard, the rods which form the frame may selectively swivel at least ninety degrees so as to remain in a perpendicular orientation relative to the seat with the canopy held over the seat regardless of which structure the harness is attached to.