The density of Ga2O3liquid in equilibrium with air has been measured at 18000to 19000C using an Ir double‐bob Archimedean method. The data yield the following description of the density of Ga2O3liquid: ρ= 4.8374(84)–0.00065(12)(T −18500C). This density‐temperature relationship is compared with the partial molar volume of Ga2O3in glasses in the systems CaO–Ga2O3–SiO2and Na2O–Ga2O3–SiO2, corrected to the glass transition temperature using thermal expansivities. The comparison illustrates that a positive excess volume term is required in these systems at low temperature. This observation is similar to those deduced from studies of the partial molar volumes of Fe2O3and Al2O3i