百日菊属（学名：Zinnia）是菊科下的一个属，为一年生或多年生草本或为亚灌木植物。该属共有约20种，分布于美洲。

Zinnia is a genus of plants of the sunflower tribe within the daisy family. They are native to scrub and dry grassland in an area stretching from the Southwestern United States to South America, with a centre of diversity in Mexico. Members of the genus are notable for their solitary long-stemmed flowers that come in a variety of bright colors. The genus name honors German botanist Johann Gottfried Zinn (1727–59).