In a medium bowl, whisk together mayonnaise, sour cream, and milk until smooth and well combined.
Add dill pickle juice, pickles, dill, garlic powder, onion powder, salt, and pepper. Stir until all the ingredients are evenly incorporated.
Transfer the dressing to a jar or airtight container. Refrigerate for at least 30 minutes to allow the flavors to develop.
Serve as a salad dressing, dip, or sauce for your favorite dishes. Store any leftovers in the refrigerator for up to 3–4 days.