A hearth () is the place in a home where a fire is or was traditionally kept for home heating and for cooking, usually constituted by at least a horizontal hearthstone and often enclosed to varying degrees by any combination of reredos (a low, partial wall behind a hearth), fireplace, oven, smoke hood, or chimney. Hearths are usually composed of masonry such as brick or stone. For centuries, the hearth was such an integral part of a home, usually its central and most important feature, that the 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 the modern era, since the advent of central heating, hearths are usually less central to most people's daily life because the heating of the home is instead done by a furnace or a heating stove, and cooking is instead done with a kitchen stove/range (combination cooktop and oven) alongside other home appliances; thus many homes built in the 20th and 21st centuries do not have hearths. Nonetheless, many homes still have hearths, which still help serve the purposes of warmth, cooking, and comfort.

Before the industrial era, a common design was to place a hearth in the middle of the room as an open hearth, with the smoke rising through the room to a smoke hole in the roof. In later designs which usually had a more solid and continuous roof, the hearth was instead placed to the side of the room and provided with a chimney.

In fireplace design, the hearth is the part of the fireplace where the fire burns, usually consisting of fire brick masonry at floor level or higher, underneath the fireplace mantel.