We report a first-principles study for assessing the roles of rare-earth (RE) dopants (Y and Ce) on adhesion of the thermally grown alpha-Al2O3/gamma-Ni(Al) interface. The effects on adhesion of temperature, stoichiometry, Al chemical activity, and Y/Ce segregation are thoroughly examined, and the results are compared with those of impurity S. A major discovery is that very similar to (perhaps more efficiently than) Hf, doping with Y provides several concurrent benefits, including increasing the adhesion of the weak stoichiometric interface by a factor of similar to 3. Doping with Ce almost doubles the adhesion of the stoichiometric interface, but it may reduce the adhesion of the strong Al-rich interface by similar to 20 %. Also, notably, Ce has a very strong capability of gettering detrimental S in Ni, which is almost triple those of Y and Hf.