Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the ground turkey, chopped spinach, crumbled feta cheese, breadcrumbs, minced garlic, chopped onion, egg, oregano, salt, and pepper.
Mix all the ingredients together until well combined. You can use your hands or a spatula; just be gentle to avoid overmixing.
With wet hands, shape the mixture into meatballs, about 1.5 inches in diameter, and place them on the prepared baking sheet.
Drizzle the olive oil over the meatballs to help them brown in the oven.
Bake the meatballs in the preheated oven for about 20-25 minutes, or until they are cooked through and golden brown.
For extra flavor, you can serve the meatballs with marinara sauce on the side.