Preheat oven to 400°F.
Heat olive oil in a skillet over medium-low heat. Add the onion, garlic, parsley, thyme, salt and pepper. Cook, stirring frequently, until the onions are translucent (about 7-10 minutes). Remove from the heat and stir in the Worcestershire sauce. Set aside to cool slightly.
In a large bowl, use a fork to gently combine the ground beef, onion mixture, breadcrumbs, milk and eggs.
Divide the mixture into 6 equal portions and shape into oval balls. Wrap each ball with one strip of bacon.
Arrange bacon-wrapped meatloaves on a parchment-lined or foil-lined rimmed baking sheet that has been lightly coated with nonstick spray.
In a small bowl, stir together ketchup, brown sugar and vinegar. Brush a light coating of the ketchup mixture on top of each meatloaf, reserving extra glaze for later.
Bake until the fat from the bacon has rendered, about 20 minutes.
Increase the oven temperature to 425°F. Brush meatloaves with remaining ketchup mixture. Continue to bake until the meatloaves are cooked through and the bacon is crisp, about 15 more minutes. If using an instant-read thermometer, the meatloaves should reach an internal temperature of 155-160°F. Serve hot.