2,3-dihydroxybenzoate 2,3-dioxygenase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are 2,3-dihydroxybenzoic acid and oxygen. Its product is 2-carboxy-cis,cis-muconic acid.
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 2,3-dihydroxybenzoate:oxygen 2,3-oxidoreductase (decyclizing). This enzyme is also called 2,3-dihydroxybenzoate 2,3-oxygenase.