In enzymology, a trithionate hydrolase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are trithionate and H<sub>2</sub>O, whereas its 3 products are thiosulfate, sulfate, and H<sup>+</sup>.
This enzyme belongs to the family of hydrolases, specifically those acting on sulfur-sulfur bonds. The systematic name of this enzyme class is trithionate thiosulfohydrolase. This enzyme participates in sulfur metabolism.