Preheat the oven to 400°F (200°C), line a baking sheet with parchment, and lightly squeeze the zucchini so it is damp but not dripping.
Place the ground chicken in a large bowl and add zucchini, breadcrumbs, Parmesan, egg, garlic powder, Italian seasoning, salt, and pepper.
Mix gently with clean hands until the ingredients are evenly distributed, stopping as soon as the mixture comes together.
Shape the mixture into evenly sized meatballs and arrange them on the prepared baking sheet with a little space between each.
Bake for 16–20 minutes, turning once if desired, until the meatballs are lightly browned and fully cooked through.
Remove them from the oven and let them rest for 3–4 minutes so the juices redistribute inside.
Serve with marinara sauce, pasta, rice, salad, or place them inside toasted rolls for easy sandwiches.