In enzymology, a diiodotyrosine transaminase (EC 2.6.1.24) is an enzyme that catalyzes the chemical reaction

3,5-diiodo-L-tyrosine + 2-oxoglutarate ${\displaystyle \rightleftharpoons }$ 4-hydroxy-3,5-diiodophenylpyruvate + L-glutamate

Thus, the two substrates of this enzyme are 3,5-diiodo-L-tyrosine and 2-oxoglutarate, whereas its two products are 4-hydroxy-3,5-diiodophenylpyruvate and L-glutamate.

This enzyme belongs to the family of transferases, specifically the transaminases, which transfer nitrogenous groups. The systematic name of this enzyme class is 3,5-diiodo-L-tyrosine:2-oxoglutarate aminotransferase. Other names in common use include diiodotyrosine aminotransferase, halogenated tyrosine aminotransferase, and halogenated tyrosine transaminase. It employs one cofactor, pyridoxal phosphate.