The optical response of Au/SiO2 nanocomposite films at temperatures spanning the transition to the liquid state has been measured. The change in the optical constants of gold from those corresponding to the crystalline material to those of the liquid occurs gradually and at temperatures below the bulk melting point. The similarity of the temperature-induced changes in the Au interband absorption edge to that observed with decreasing particle size suggests that a gradual transition to the liquid phase also occurs in small particles.