Natural gas, although predominantly comprised of methane, often contains small amounts of heavier hydrocarbons that contribute to its thermodynamic and transport properties. In this manuscript, we review the current literature and present new correlations for the viscosity of the pure fluids n-octane, n-nonane, and n-decane that are valid over a wide range of fluid states, from the dilute gas to the dense liquid. The new correlations represent the viscosity to within the uncertainty of the best experimental data and will be useful for engineers working on viscosity models for natural gas and other hydrocarbon mixtures. Published by Elsevier B.V.