Magnolia grandiflora, commonly known as the southern magnolia or bull bay, is a flowering tree in the family Magnoliaceae native to the Southeastern United States coastal plain, from Virginia to central Florida, and west to East Texas. Reaching 27.5 m (90 ft) in height, it is a large, striking evergreen tree, with large, dark-green leaves up to 20 cm (7+3⁄4 in) long and 12 cm (4+3⁄4 in) wide, and large, white, fragrant flowers up to 30 cm (12 in) in diameter.

Although endemic to the evergreen lowland subtropical forests on the Gulf and South Atlantic coastal plain, M. grandiflora is widely cultivated in warmer areas around the world. The timber is hard and heavy, and has been used commercially to make furniture, pallets, and veneer.