Metalloproteinases (or metalloproteases) constitute a family of enzymes from the group of proteinases, classified by the nature of the most prominent functional group in their active site.

There are two subgroups of metalloproteinases:

• exopeptidases: metalloexopeptidases (EC number: 3.4.17).
• endopeptidases: metalloendopeptidases (3.4.24). Well known metalloendopeptidases include ADAM proteins and matrix metalloproteinases.