Place the olive oil, onions, and garlic in a large pot until softened, about 5 minutes.
Add the carrots, celery, chicken broth, and water to the onion and garlic. Bring to a boil. Let it boil until the vegetables are cooked.
Add the noodles, chicken, parsley, poultry seasoning, salt, and pepper, and let it boil until the noodles are cooked. Serve immediately.