Melt butter in a skillet. Cook onion and garlic in melted butter for 5 minutes, stirring occasionally. Place mixture in a large bowl and let cool for 5 minutes.
Meanwhile, combine turkey, bread crumbs, egg, 1/4 cup of the ketchup, Worcestershire sauce, salt, and pepper with onion mixture. I use a food processor, pulsing until mixed.
Press meatloaf into an 8"x4"-inch loaf pan or shape into a freeform oval shape and place on a baking sheet. Spread remaining ketchup on top.
Bake in a 350°F. oven for 45-55 minutes. Meatloaf is done when the Internal temperature at the thickest portion of the loaf is 165°F.
Remove from oven and let stand 5 minutes before serving.