白尾鹞（学名：Circus cyaneus）为鹰科鹞属的鸟类。多生活于沼泽以及牧场。该物种的模式产地在欧洲、非洲。

• 中国国家重点保护动物等级：二级

The hen harrier (Circus cyaneus) or northern harrier (in the Americas) is a bird of prey. It breeds throughout the northern parts of the northern hemisphere in Canada and the northernmost USA, and in northern Eurasia. This species is polytypic, with two subspecies. Marsh hawk is a historical name for the American form. The term "hen harrier" refers to its former habit of preying on free-ranging fowl.