The classical kinetic theory of polyatomic gases has been applied to calculate the traditional transport properties of heavy water (D₂O) in the dilute gas limit using two highly accurate ab initio pair potentials. Results are reported for shear viscosity, thermal conductivity and the product of molar density and self-diffusion coefficient at temperatures between 250 and 2500 K. The expanded uncertainty (coverage factor k = 2) of the computed values is estimated to be 2% for viscosity and self-diffusion and 2%–4%, depending on temperature, for thermal conductivity. For the most part, the agreement with the available experimental data is satisfactory.