Preheat oven to 400°F. Line a baking sheet with parchment paper.
In a large mixing bowl, combine ground chicken, parmesan cheese, salt, black pepper, minced garlic, chopped parsley, and olive oil. Mix gently with a fork until just combined. Do not overmix.
Using a 2-tablespoon cookie scoop, portion out the mixture into 12 equal portions on the prepared baking sheet, spacing them about 2 inches apart.
With damp hands, roll each portion into a smooth, tight ball.
Bake for 20 minutes until golden brown and internal temperature reaches 165°F.
While meatballs are baking, make the sauce. In a small saucepan over medium-low heat, melt the butter completely. Remove from heat immediately once melted.
Grate the garlic cloves directly into the melted butter. Add lemon juice and stir. Season with salt and pepper to taste.
Transfer cooked meatballs to a serving platter. Drizzle the garlic butter sauce over the meatballs. Garnish with extra parsley if desired.
Serve immediately while hot.