α-Mannosidase (EC 3.2.1.24, α-D-mannosidase, p-nitrophenyl-α-mannosidase, α-D-mannopyranosidase, 1,2-α-mannosidase, 1,2-α-D-mannosidase, exo-α-mannosidase) is an enzyme involved in the cleavage of the α form of mannose.

Its systematic name is α-D-mannoside mannohydrolase.

[3][4] Humans express the following three α-mannosidase isoenzymes: It can be utilized in experiments that determine the effects of the presence or absence of mannose on specific molecules, such as recombinant proteins that are used in vaccine development.

[5] A deficiency can lead to α-mannosidosis.

This EC 3.2 enzyme-related article is a stub.