Rumah Gadang (Minangkabau: "big house") or Rumah Bagonjong "house for the Minangkabau people" (Minangkabau: "spired roof house") are the traditional homes (Indonesian: "rumah adat") of the Minangkabau in West Sumatra, Indonesia. The architecture, construction, internal and external decoration, and the functions of the house reflect the culture and values of the Minangkabau. A Rumah Gadang serves as a residence, a hall for family meetings, and for ceremonial activities. In the matrilineal Minangkabau society, the Rumah Gadang is owned by the women of the family who live there; ownership is passed from mother to daughter.

The houses have a dramatic curved roof structure with multi-tiered, upswept gables. Shuttered windows are built into walls incised with profusely painted floral carvings. The term Rumah Gadang usually refers to the larger communal homes; however, smaller single residences share many of its architectural elements.

In West Sumatra, traditional Rumah Gadang reflects the Minangkabau people and has become the symbol of West Sumatra and Minangkabau culture. Throughout the region, numerous buildings demonstrate the design elements of Rumah Gadang, from genuine vernacular timber masonry structures built for customary ceremonies to the more mundane modern structures like those of government offices and public facilities. Today, Rumah Gadang architectural elements, especially its gonjong horn-like curved roof, can be found in modern structures, such as governor and regencies office buildings, marketplaces, hotels, the facades of Padang restaurants, and Minangkabau International Airport. An istano basa, however, is the largest and most magnificent example of this traditional style.