In cooking, a sauce is a liquid, cream, or semi-solid food, served on or used in preparing other foods. Most sauces are not normally consumed by themselves; they add flavor, moisture, and visual appeal to a dish. Sauce is a French word taken from the Latin salsa, meaning salted. Possibly the oldest recorded European sauce is garum, the fish sauce used by the Ancient Romans, while doubanjiang, the Chinese soy bean paste is mentioned in Rites of Zhou in the 3rd century BC.

Sauces need a liquid component. Sauces are an essential element in cuisines all over the world.

Sauces may be used for sweet or savory dishes. They may be prepared and served cold, like mayonnaise, prepared cold but served lukewarm like pesto, cooked and served warm like bechamel or cooked and served cold like apple sauce. They may be freshly prepared by the cook, especially in restaurants, but today many sauces are sold premade and packaged like Worcestershire sauce, HP Sauce, soy sauce or ketchup. Sauces for salad are called salad dressing. Sauces made by deglazing a pan are called pan sauces.

A chef who specializes in making sauces is called a saucier.