An attractive strategy to improve the performance of water oxidation catalysts would be to anchor a homogeneous molecular catalyst onto a heterogeneous solid surface to create a hybrid catalyst. The idea of this combined system is to take advantage of the individual properties of each of the two catalyst components. We use DFT calculations to determine the stability and activity of a model hybrid water oxidation catalyst that consists of a dimeric Ir complex attached on the IrO2(1 1 0) surface through two oxygen atoms. We find that homogeneous catalysts can be anchored to oxide surfaces without a significant loss of activity. Hence, the design of hybrid systems that benefit from both the high tunability of the activity of homogeneous catalysts and the stability of heterogeneous systems seems feasible.