大黍（学名：Panicum maximum）是一种禾本科植物。这种植物于20世纪30年代传入中国广州。原产非洲，现广布于热带和亚热带地区。

Megathyrsus maximus, known as Guinea grass and green panic grass in English, is a large perennial bunch grass that is native to Africa, Palestine, and Yemen. It has been introduced in the tropics around the world. Until 2003, it was named Urochloa maxima. It was moved to genus Megathyrsus, which it shares with one other species, M. infestus.