In this article, experimental data are reported concerning viscosity measurements carried out on olive paste at different phases of the extraction process. Using these data, a rheological analysis of experimental samples was carried out. The analysis showed that the actual olive paste rheological behavior is correctly described by a non-Newtonian model expressed by a power law model, well known in the literature. Numerical values for the power law parameters were determined at each step of the olive milling process. Moreover, a deeper analysis was carried out to investigate the capability of three different analytical models to predict the relative viscosity of olive paste as a function of solids volume fraction at different phases of the extraction process. Model predictions are compared to experimental data and discussed.