Preheat your oven to 400°F (200°C).
In a mixing bowl, combine ground chicken, breadcrumbs, grated Parmesan, chopped parsley, egg, minced garlic, onion powder, Italian seasoning, salt, black pepper, and milk. Mix until just combined; do not overmix.
Using your hands, shape the mixture into meatballs about 1.5 inches in diameter, placing them on a baking sheet lined with parchment paper or sprayed with cooking spray.
Bake the meatballs in the preheated oven for 20 minutes or until they are cooked through and golden brown.
While the meatballs are baking, heat olive oil in a large skillet over medium heat. Once hot, add the meatballs and cook for an additional 5 minutes, rotating them carefully to brown all sides.
Serve hot over pasta, in a sub, or as desired.