In enzymology, a formate dehydrogenase (cytochrome-c-553) () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are formate and ferricytochrome c-553, whereas its two products are CO<sub>2</sub> and ferrocytochrome c-553.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with a cytochrome as acceptor. The systematic name of this enzyme class is formate:ferricytochrome-c-553 oxidoreductase.