In enzymology, a pyridoxine 4-oxidase (EC 1.1.3.12) is an enzyme that catalyzes the chemical reaction

pyridoxine + O₂ ${\displaystyle \rightleftharpoons }$ pyridoxal + H₂O₂

Thus, the two substrates of this enzyme are pyridoxine and O₂, whereas its two products are pyridoxal and H₂O₂.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with oxygen as acceptor. The systematic name of this enzyme class is pyridoxine:oxygen 4-oxidoreductase. Other names in common use include pyridoxin 4-oxidase, and pyridoxol 4-oxidase. This enzyme participates in vitamin B₆ metabolism. It employs one cofactor, FAD.