The viscosities and densities of nine binary n-alkan-1-ol systems, 1-propanol + 1-butanol, 1-propanol + 1-pentanol, 1-butanol + 1-pentanol, 1-butanol + 1-nonanol, 1-butanol + 1-decanol, 1-pentanol + 1-octanol, 1-heptanol + 1-octanol, 1-nonanol + 1-decanol, and 1-decanol + 1-undecanol, were experimentally determined over the entire composition range at temperatures of 293.15 K and 298.15 K and at atmospheric pressure. The experimental viscosity data were correlated by the McAllister three-body and four-body models and were used to test the predictive capability of the generalized corresponding state principle (GCSP) method.