Heat oven to 400 degrees.
Combine ground turkey, chopped onion, stuffing mix, eggs, water, and half of the ketchup in a large bowl. Mix well.
Spray a loaf pan and add your mixture. Flatten the top and top with remaining ketchup.
Bake for 50 minutes or until the meatloaf registers 170 degrees internally.
Let it stand 5 minutes before cutting in.