In enzymology, a progesterone monooxygenase (EC 1.14.99.4) is an enzyme that catalyzes the chemical reaction

progesterone + AH₂ + O₂ ${\displaystyle \rightleftharpoons }$ testosterone acetate + A + H₂O

The 3 substrates of this enzyme are progesterone, AH₂, and O₂, whereas its 3 products are testosterone acetate, A, and H₂O.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O₂ as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O miscellaneous.^{[clarification needed]} The systematic name of this enzyme class is progesterone,hydrogen-donor:oxygen oxidoreductase (hydroxylating). This enzyme is also called progesterone hydroxylase.