牛背鹭（学名：Bubulcus ibis），又称黄头鹭，是鹳形目鹭科牛背鹭属中仅有的一个种。

身长约51cm，与其他鹭的区别在体型较粗壮，颈较短而头圆，嘴较短厚。

• 繁殖羽：体白，头、颈、胸沾橙黄；虹膜、喙、腿及眼先短期呈亮红色，余时橙黄。
• 非繁殖羽：体白，仅部分鸟额部沾橙黄。虹膜－黄色；喙－黄色；脚－暗黄至近*黑。叫声－于巢区发出呱呱叫声，余时寂静无声。

The cattle egret (Bubulcus ibis) is a cosmopolitan species of heron (family Ardeidae) found in the tropics, subtropics and warm temperate zones. It is the only member of the monotypic genus Bubulcus, although some authorities regard its two subspecies as full species, the western cattle egret and the eastern cattle egret. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.