Ceruloplasmin (or caeruloplasmin) is a ferroxidase enzyme that in humans is encoded by the CP gene.
Ceruloplasmin is the major copper-carrying protein in the blood, and in addition plays a role in iron metabolism. It was first described in 1948. Another protein, hephaestin, is noted for its homology to ceruloplasmin, and also participates in iron and probably copper metabolism.