Potato chips (North American English and Australian English; often just chips) or crisps (British English and Hiberno-English) are thin slices of potato (or a thin deposit of potato paste) that have been deep-fried, baked, or air-fried until crunchy. They are commonly served as a snack, side dish, or appetizer. The basic chips are cooked and salted; additional varieties are manufactured using various flavorings and ingredients including herbs, spices, cheeses, other natural flavors, artificial flavors, and additives.

Potato chips form a large part of the snack food and convenience food market in Western countries. The global potato chip market generated total revenue of US$16.49 billion in 2005. This accounted for 35.5% of the total savory snacks market in that year (which was $46.1 billion overall).

The earliest known recipe for potato chips is in the English cook William Kitchiner's book The Cook's Oracle published in 1817 in London, which was a bestseller in the United Kingdom and the United States. The 1822 edition's recipe for "Potatoes fried in Slices or Shavings" reads "peel large potatoes... cut them in shavings round and round, as you would peel a lemon; dry them well in a clean cloth, and fry them in lard or dripping". An 1825 British book about French cookery calls them "Pommes de Terre frites" (second recipe) and calls for thin slices of potato fried in "clarified butter or goose dripping", to be drained once crisp and sprinkled with salt. Early recipes for potato chips in the US are found in Mary Randolph's Virginia House-Wife (1824) and in N.K.M. Lee's Cook's Own Book (1832), both of which explicitly cite Kitchiner.

A legend associates the creation of potato chips with Saratoga Springs, New York, decades later than the first recorded recipe. By the late nineteenth century, a popular version of the story, today known to be untrue, attributed the dish to George Crum, a cook at Moon's Lake House who was trying to appease an unhappy customer on August 24, 1853. The customer kept sending back his French-fried potatoes, complaining that they were too thick, too "soggy", or not salted enough. Frustrated, Crum sliced several potatoes extremely thin, fried them to a crisp, and seasoned them with extra salt – to his surprise, the customer loved them. They soon came to be called "Saratoga Chips", a name that persisted into the mid-twentieth century. A version of this story was popularized in a 1973 national advertising campaign by St. Regis Paper Company which manufactured packaging for chips, claiming that Crum's customer was Cornelius Vanderbilt. The story is today known to be a myth, and historians and academics have identified a number of problems with the story: Vanderbilt was in Europe during the alleged encounter, the Moons didn't purchase the Lake House until 1854, and crispy fried potatoes were not unknown to Saratoga in 1853. However, the story remains frequently cited in popular media.

In the 20th century, potato chips spread beyond chef-cooked restaurant fare and began to be mass-produced for home consumption. The Dayton, Ohio-based Mikesell's Potato Chip Company, founded in 1910, identifies as the "oldest potato chip company in the United States". New Hampshire-based Granite State Potato Chip Factory, founded in 1905 and in operation until 2007, was one of America's first potato chip manufacturers.

In an idea originated by the Smiths Potato Crisps Company Ltd, formed in 1920, Frank Smith packaged his chips in greaseproof paper bags and attached a twist of salt, and sold them around London. The potato chip remained otherwise unseasoned until the 1950s. After some trial and error, in 1954, Joe "Spud" Murphy, the owner of the Irish crisps company Tayto, and his employee Seamus Burke, produced the world's first seasoned chips: cheese & onion. Companies worldwide sought to buy the rights to Tayto's technique. Walkers of Leicester, England, produced cheese & onion the same year. Golden Wonder (Smith's main competitor at the time) also started to produce cheese & onion, and Smith's countered with salt & vinegar (tested first by their north-east England subsidiary Tudor and then launched nationally in 1967), starting a two-decade-long flavor war.

The first flavored chips in the United States, barbecue flavor, were being manufactured and sold by 1954. In 1958, Herr's was the first company to introduce barbecue-flavored potato chips in Pennsylvania.

Chips sold in markets were usually sold in tins or scooped out of storefront glass bins and delivered by horse and wagon. Early potato chip bags were made of wax paper with the ends ironed or stapled together. At first, potato chips were packaged in barrels or tins, which left chips at the bottom stale and crumbled.