In enzymology, a peptide-aspartate beta-dioxygenase (EC 1.14.11.16), a member of the alpha-ketoglutarate-dependent hydroxylases superfamily, is an enzyme that catalyzes the chemical reaction

peptide-L-aspartate + 2-oxoglutarate + O₂ ${\displaystyle \rightleftharpoons }$ peptide-3-hydroxy-L-aspartate + succinate + CO₂

The 3 substrates of this enzyme are peptide-L-aspartate, 2-oxoglutarate, and O₂, whereas its 3 products are peptide-3-hydroxy-L-aspartate, succinate, and CO₂.

It employs one cofactor, iron.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O₂ as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O₂ with 2-oxoglutarate as one donor, and incorporation of one atom o oxygen into each donor. The systematic name of this enzyme class is peptide-L-aspartate,2-oxoglutarate:oxygen oxidoreductase (3-hydroxylating). Other names in common use include aspartate beta-hydroxylase, and aspartylpeptide beta-dioxygenase.