The effect of the nickel/zirconia (111) interface on oxygen vacancy formation energies in zirconia is investigated utilizing first principles simulation. The relationship between vacancy formation energy and the Fermi level is found to be similar to that calculated in the bulk system when the vacancy is located at three oxygen layers away from the interface. Moreover, we find a modulation of about 1 eV in the formation energies when the vacancies are located closer to the interface and relate this to the interface electronic states. [DOI: 10.1380/ejssnt.2010.93]