In enzymology, a dCTP diphosphatase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are dCTP and H<sub>2</sub>O, whereas its two products are dCMP and diphosphate.
This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides. The systematic name of this enzyme class is dCTP nucleotidohydrolase. Other names in common use include deoxycytidine-triphosphatase, dCTPase, dCTP pyrophosphatase, deoxycytidine triphosphatase, deoxy-CTPase, and dCTPase. This enzyme participates in pyrimidine metabolism.