Abstract: A lawn mower blade stop for a rotary lawn mower. The blade stop is preferably formed from first and second L-shaped members welded together to form a U-shaped channel with a plate serving as a barrier to rotation of the blade. The U-shaped channel is received on and makes at least three point contact with the inside of a skirt of a rotary lawn mower housing. A threaded member making at least one-point contact with the outside of the skirt fixes the blade stop in a plane with respect to the skirt.