冠海豹（学名：Cystophora cristata）是北极的一种海豹。牠们分布在中及西北冰洋，东临斯瓦尔巴群岛，西至圣罗伦斯湾。

成年公冠海豹的鼻子上有一可以膨涨及凸出的附属器官。当公冠海豹4岁大时这个凸出物就开始发育。公海豹透过令凸出物膨胀，令其头部看似大些。成年公海豹平均长2.6米，重410公斤。牠们由出生时就已经有明显的两性异形：雌冠海豹是较为细小的，只有2.03米长及重低于300公斤。牠们呈银色，散布了黑色及不规则的斑纹。头部较身体其他部份深色，但没有斑纹。幼冠海豹出生时长约1米及重24公斤。出生时呈背部灰蓝色，腹部呈淡奶白色。

The hooded seal (Cystophora cristata) is a large phocid found only in the central and western North Atlantic, ranging from Svalbard in the east to the Gulf of St. Lawrence in the west. The seals are typically silver-grey in colour, with black spots that vary in size covering most of the body. Hooded seal pups are known as "blue-backs" because their coats are blue-grey on the back with whitish bellies, though this coat is shed after 14 months of age when the pups molt.