Preheat oven to 400 F. Line a rimmed baking sheet with silicone baking sheet or foil.
Place the chicken pieces into a mixing bowl.
Place the sliced zucchini, sliced red onion, grape tomatoes, and kalamata olives into another mixing bowl.
Whisk together the olive oil, lemon juice, garlic powder, dried oregano, dried thyme. Pour half over the chicken pieces and the other half over the veggies. Gently toss to incorporate the dressing throughout each bowl.
Spread the veggies into an even layer on the prepared baking dish. Place the chicken pieces in a single layer (so they will cook through properly) around and over the veggies. Sprinkle the feta cheese crumbles over the top.
Bake in the preheated oven for 30 to 35 minutes, or until largest chicken pieces are cooked through. Season with salt and pepper to taste.
Serve Sheet Pan Greek Chicken with parsley garnish, and optional side salad or rice. Enjoy!