The oxygen ion conductivity of polycrystalline samples of Lu doped ceria is studied using impedance spectroscopy. Lutetium doped ceria is of particular interest as Lu has a similar ionic radius as the host cation Ce. The change of the ionic conductivity as a function of the Lu dopant fraction is investigated in detail revealing a similar behavior as Sm doped ceria that has one of the highest ionic conductivity in ternary cerium oxides. In comparison with simulations, the experimental dependence of the conductivity on the dopant fraction reveals that migration barriers for oxygen vacancy jumps around Lu ions are slightly higher than for jumps in pure ceria. The absolute conductivity is small due to the strong trapping of oxygen vacancies near Lu dopants.