Preheat air fryer to 400°F.
In a bowl, combine ground beef, breadcrumbs, beaten egg, minced garlic, grated parmesan, chopped parsley, salt, pepper, and oregano. Mix gently until just combined, avoiding overworking the meat.
Form the mixture into 12 equal-sized balls, about 1.5 inches each. Lightly brush each meatball with olive oil to promote browning.
Arrange the meatballs in a single layer in the air fryer basket, ensuring they don't touch. Cook at 400°F for 12 minutes, flipping halfway through.
Check for doneness by ensuring the meatballs are browned on the outside and the internal temperature reaches 160°F using a meat thermometer.
Let the meatballs rest for 5 minutes before serving. This allows the juices to redistribute for a tender bite.