Bring a large pot of lightly salted water to a boil. Cook elbow macaroni in the boiling water, stirring occasionally, until tender yet firm to the bite, about 8 minutes.
Meanwhile, combine tuna, bell pepper, celery, carrot, radishes, green onions, and parsley in a large bowl.
Drain macaroni and rinse in cold water. Drain again and add to the bowl with the tuna mixture.
Combine mayonnaise, ranch dressing, Parmesan cheese, black pepper, and salt in a small bowl. Pour dressing over salad and toss to coat. Refrigerate at least 2 hours before serving.
