Protactinyl nitrate, protactinium(V) oxynitrate, or erroneously known as protactinium nitrate, is a radioactive chemical compound with the formula PaO(NO3)3·xH2O (1.5 ≤ x ≤ 4).

It is a white solid that readily hydrolyzes to protactinium(V) oxide in moist air.

This compound is a common commercial source of protactinium.

Lower concentrations of nitric acid cannot be used, due to the hydrolysis of the compound.

[1] Protactinyl nitrate decomposes at 400 °C to protactinium(V) oxide.