Add 3/4 cup plain Greek yogurt, 1/2 cup mayonnaise, and 1/2 cup buttermilk to a medium mixing bowl.
Add 1 teaspoon garlic powder, 1 teaspoon onion powder, 1 teaspoon dried dill, 2 teaspoons dried parsley, and 1/2 teaspoon salt.
Whisk everything together until fully combined and creamy, making sure the herbs are evenly distributed.
Transfer the ranch dressing to an airtight jar and refrigerate for at least 30 minutes before using so the flavors can fully develop.