Ranch dressing is an American salad dressing usually made from buttermilk, salt, garlic, onion, mustard, herbs (commonly chives, parsley and dill), and spices (commonly pepper, paprika and ground mustard seed) mixed into a sauce based on mayonnaise or another oil emulsion. Sour cream and yogurt are sometimes used in addition to, or as a substitute for, buttermilk and mayonnaise.

Ranch has been the best-selling salad dressing in the United States since 1992, when it overtook Italian. It is also popular in the United States and Canada as a dip, and as a flavoring for potato chips and other foods. In 2017, 40% of Americans named ranch as their favorite dressing, according to a study by the Association for Dressings and Sauces.