Preheat an oven to 350 degrees F (175 degrees C). Grease a 9x5 inch loaf pan.
Mix the beef, pork, egg, apple, onion, Worcestershire sauce, salt, and pepper in a mixing bowl until evenly mixed. Add the Cheddar cheese, bread crumbs, and oats; mix again until evenly mixed. Pack the meat mixture into the prepared loaf pan.
Bake in the preheated oven until no longer pink in the center, about 1 hour. An instant-read thermometer inserted into the center should read at least 160 degrees F (72 degrees C). Allow the meatloaf to rest for 10 minutes before slicing to keep the meat from crumbling.
