菊科（学名：Asteraceae）是双子叶植物纲菊目的一个非常大和普遍的科。菊科是双子叶植物中属最多的一个科，约有1600属，23600种和13个亚科，是双子叶植物的第一大科。广泛分布在全世界，但热带地区较少，中国有约200属2000多种，包括了菊花、蒲公英、大蓟、小蓟、茵陈、艾叶、青蒿、紫苑、鹅不食草等中草药。被子植物中，菊科的种类仅次于兰科，是被子植物的第二大科（两者的确切数目尚不清楚，故事实上两科数目孰多也不能断定）。菊科的学名是由模式属紫菀属（Aster）而来，是「星形」的意思，指菊科植物的头状花序似星形。

Asteraceae or Compositae (commonly referred to as the aster, daisy, composite, or sunflower family) is an exceedingly large and widespread family of flowering plants (Angiospermae).

The family has more than 23,600 currently accepted species, spread across 1,620 genera (list) and 13 subfamilies. In terms of numbers of species, the Asteraceae are rivaled only by the Orchidaceae. (Which of the two families is actually larger is unclear, owing to uncertainty about exactly how many species exist in each family.) Many members have composite flowers in the form of flower heads (capitula or pseudanthia) surrounded by involucral bracts. When viewed from a distance, each capitulum may have the appearance of being a single flower. The name "Asteraceae" comes from the type genus Aster, from the Greek ἀστήρ, meaning star, and refers to the star-like form of the inflorescence. "Compositae" is an older but still valid name which refers to the fact that the family is one of the few angiosperm ones to have composite flowers.