The optical constants of liquid UO2, n and k, were determined from reflection measurements at the 1064-nm wavelength in the near infrared. The reflectivities of the specimen surfaces were measured with polarized light in a pressurized integrating sphere laser reflectometer, and the respective values of the refractive index n and the absorption constant k of the specimen material were calculated. Consistent values resulted in the 3120 to 4000 K temperature range with little dependence on the temperature. Mean values are n = 2.0 and k = 0.51 in this range.