Preheat oven to 400°F (204°C) and line a baking sheet with parchment paper.
In a large bowl, combine ground chicken, breadcrumbs, egg, garlic, green onions, salt, and pepper.
Form the mixture into approximately 20 meatballs, about 1.5 inches in diameter.
Place meatballs on the prepared baking sheet and bake for 18 to 20 minutes, or until the internal temperature reaches 165°F (74°C).
In a separate bowl, whisk together the buffalo hot sauce and melted butter.
Toss the cooked meatballs in the sauce until evenly coated and serve immediately.