Mashed potato or mashed potatoes, colloquially known as mash, is a dish made by mashing boiled or steamed potatoes, usually with added milk, butter, salt and pepper. It is generally served as a side dish to meat or vegetables. Roughly mashed potatoes are sometimes called smashed potatoes. Dehydrated instant mashed potatoes and frozen mashed potatoes are available. Mashed potatoes are an ingredient in other dishes, such as dumplings and gnocchi.

The potato is a starchy root vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are tubers of the plant Solanum tuberosum, a perennial in the nightshade family Solanaceae.