Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper and lightly coat with cooking spray.
In a large mixing bowl, combine ground chicken, red onion, feta cheese, dill, mint, lemon zest, lemon juice, breadcrumbs, egg, olive oil, garlic powder, salt, and pepper.
Using a cookie scoop or spoon, portion about 2 tablespoons of mixture and shape into meatballs. Arrange on the prepared baking sheet.
Bake for 20 minutes or until golden brown and the internal temperature reaches 165°F (75°C).
Cook the rice or orzo according to package instructions.
Prepare the Greek salad dressing by whisking together vinegar, lemon zest, lemon juice, olive oil, garlic powder, Dijon mustard, oregano, salt, and pepper.
Add cucumber, tomatoes, bell pepper, olives, red onion, herbs, and feta to a large bowl. Toss with the dressing until evenly coated.
Make the yogurt dill sauce by combining Greek yogurt, lemon juice, dill, garlic powder, salt, and olive oil in a small bowl. Stir until smooth.
Assemble the Easy Greek Chicken Meatball Bowls by dividing rice among serving bowls. Top with meatballs, cucumber salad, and a generous drizzle of yogurt dill sauce.
Garnish with additional fresh herbs or feta cheese if desired.