六鳃鲨科（学名Hexanchidae）是板鳃亚纲六鳃鲨目的其中一科。

六鳃鲨科下分3个属，如下：

Cow sharks are a family, the Hexanchidae, of sharks characterized by an additional pair or pairs of gill slits. Its 37 species are placed within the 10 genera Gladioserratus, Heptranchias, Hexanchus, Notidanodon, Notorynchus, Pachyhexanchus, Paraheptranchias, Pseudonotidanus, Welcommia, and Weltonia.