Interfacial melting at near eutectic compositions has been observed for three metal-silicon systems using pulsed ion beam irradiation. In all cases (Ni/Si, Co/Si, and Pt/Si), the reaction occurred below the melting temperature of either the deposited metal layer or the silicon substrate. Compositional steps in the reacted Ni/Si, Co/Si, and Pt/Si films were measured using Rutherford backscattering spectroscopy. These steps had the near eutectic compositions of Ni0.5Si0.5, Co0.73Si0.27, and Pt0.77Si0.23, respectively. The Ni/Si sample was examined using planar and cross-sectional transmission electron microscopy. It was found that the reacted layer, composed of polycrystalline NiSi and Ni2Si, formed a sharp interface with the silicon.