A brownie or broonie, is a household spirit or hobgoblin from Scottish folklore that is said to immerge from the shadows at night while the owners of the house are asleep and perform various chores and farming tasks. The human owners of the house must leave a bowl of milk or cream or some other offering for the brownie, usually by the hearth. Brownies are described as easily offended and will leave their homes forever if they feel they have been insulted or in any way taken advantage of. Brownies are characteristically full of mischief and are often said to make an example of someone or pull pranks on slothful servants. If upset for any reason, they are sometimes said to turn malicious, like boggarts.

In English and Scottish folklore, a small, busy fairy or hobgoblin believed to live in houses and barns. Not often seen, he was often heard at night, cleaning and doing housework; he also sometimes mischievously changes items in rooms. Brownies originated as domestic guardian spirits, very similar to the guardian deities in ancient Roman religion. Representations of brownies vary regionally, but they are usually detailed as ugly, brown-skinned, and covered in hair. In the ancient tales, they are usually human-sized or larger. Brownies were associated with the dead and a brownie is sometimes described as the ghost of a deceased servant who once worked in the home.

Brownies are predominately always male, but female brownies, such as Meg Mullach (or "Hairy Meg"), have occasionally been spoken of in tales as well. They are usually described as ugly and their looks are sometimes recounted as frightening or upsetting to those in the residence of the houses in which they live. The name originates from the fact that they are usually described as brown-skinned and completely covered in hair. In the earliest recollections, brownies are either the same size as humans or sometimes larger, but in later accounts, they are described as "small, wizened, and shaggy", often characterized as fat and short of stature.