Polycrystalline Al/Sc multilayer samples are grown via magnetron sputtering. The deposition of Sc onto Al results in significant intermixing between the two components. Substrate curvature, measured in-situ during deposition, reveals behavior similar to that seen in other systems where a slow diffuser is deposited onto a fast diffuser. The multilayer films are further characterized via transmission electron microscopy (TEM), analytical electron microscopy, and X-ray diffraction (XRD), confirming the intermixing and formation of a coherent crystalline phase, likely to be Al3Sc, in the interfacial regions. Nanoindentation hardness tests show that by adding a few percent of Sc to Al films and carefully controlling the location of the Sc, increases in hardness up to 6 times that of a pure Al film can be obtained.