In common historic and modern usage, a hearth ( /ˈhɑrθ/) is a brick- or stone-lined fireplace or oven often used for cooking and/or heating. For centuries, the hearth was considered an integral part of a home, often its central or most important feature. This concept has been generalized to refer to a homeplace or household, as in the terms "hearth and home" and "keep the home fires burning." In fireplace design, the hearth is often considered the visible elements of the fireplace, with emphasis upon the floor level extension of masonry associated with the fireplace mantel.

In archaeology, a hearth is a firepit or other fireplace feature of any period. Initial usage refers to a place of warmth, heat, or fire, or 'heat of earth'. Hearths are common features of many eras going back to prehistoric campsites, and may be either lined with a wide range of materials like stone or left unlined. Hearths were used for cooking, heating, and processing of some stone, wood, faunal, and floral resources. Occasionally site formation processes—e.g., farming or excavation—deform or disperse hearth features, making them difficult to identify without careful study.