Rare earth additions (Ce or Y) were studied to see how they affect the wetting properties of an Al-Zn-Mg-Cu/Al2O3 system. By using vacuum sessile drop method and casting processing, it was found that adding rare earths to the alloy can reduce contact angles and improve the interface structure. The optimal rare earth content is around 0.5wt% for Ce and 0.7wt% for Y. The interaction between rare earths and the oxide film of the Al alloys or/and α Al2O3 plaque is responsible for this improvement. Rare earth compounds like Ce2O3 and Al11Ce3 were identified at the interface. Combining rare earths with other alloying elements like Mg, Zn, and Cu enhances wetting properties more effectively than using a single rare earth element.