A bun is a small, at times sweet, bread, or bread roll. Though they come in a large number of shapes and sizes, they're most commonly hand-sized or smaller, with a round top and flat bottom.

Buns are usually made from flour, sugar, milk, yeast and butter. Common varieties contain small fruit or nuts, are topped with icing or caramel, or filled with jam or cream. Some types of buns are filled with various meats.

"Bun" might additionally refer to particular types of filled dumplings, such as Chinese baozi. Some of these types of dumplings might be bread-like in texture.

A bun is normally made from dough that has been enriched with sugar and butter and at times egg. Without any of these the dough remains to be 'bread dough' rather than 'bun dough' and the resultant product will be called a roll, rather than a bun.

List of buns