A pie is a baked dish made of a pastry dough casing that covers a filling of various sweet or savory ingredients. Pies are defined by their crusts. A filled pie has pastry lining the baking dish, and the filling is placed on top of the pastry, but left open.

A top-crust pie has the filling in the bottom of the dish and the filling covered with a pastry before baking. A two-crust pie has the filling completely enclosed in the pastry shell. Pies can be a variety of sizes, ranging from bite-size to ones designed for multiple servings.

Meat pies with fillings such as steak, cheese, steak and kidney, minced beef, or chicken and mushroom are popular in the United Kingdom, Australia and New Zealand as take-away snacks. They are also served with chips as an alternative to fish and chips at British chip shops.

Pot pies with a flaky crust and bottom are also a popular American dish, typically with a filling of meat and mixed vegetables. Frozen pot pies are often sold in individual serving

Fruit pies may be served with a scoop of ice cream, a style known in North America as pie à la mode. Many sweet pies are served this way. Apple pie is a traditional choice. This combination and the name have been popularized in the mid-1890s in the United States.