Cysteamine dioxygenase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are cysteamine and oxygen. Its product is hypotaurine.
This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O<sub>2</sub> as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O<sub>2</sub>. The systematic name of this enzyme class is 2-aminoethanethiol:oxygen oxidoreductase. Other names in common use include persulfurase, cysteamine oxygenase, and cysteamine:oxygen oxidoreductase. This enzyme participates in taurine and hypotaurine metabolism. It employs one cofactor, iron.