鼻窦，又名鼻旁窦，位于人的头颅，在头骨之间、鼻腔周围的颅骨与脸骨之内。这些鼻窦平时充满了空气，并由小管与鼻腔相连。

每个人都有四对鼻窦，根据所在的头骨部位而命名。这四对鼻窦的名称分别是：

Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sphenoidal sinuses are behind the eyes. The sinuses are named for the facial bones in which they are located.