In enzymology, pyridoxal oxidase () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are pyridoxal, water, and oxygen. Its products are 4-pyridoxic acid and hydrogen peroxide.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with oxygen as acceptor. The systematic name of this enzyme class is pyridoxal:oxygen 4-oxidoreductase. This enzyme participates in vitamin B<sub>6</sub> metabolism. It employs one cofactor, molybdenum.