山矾属（学名：Symplocos），又名灰木属，是山矾科下的一个属，为灌木或乔木植物。该属共有约250种，分布于热带和亚热带。

Symplocos is a genus of flowering plants in the order Ericales. It contains about 300 species distributed in Asia and the Americas. Many species grow in humid tropical regions. This is sometimes considered to be the only genus in family Symplocaceae. Plants in this family are shrubs and trees with white or yellow flowers.