The present study investigated the turbulent characteristics and aerodynamic performance of a ridge iced airfoil using RANS as well as LES. The ridge ice shape selected from the literature was placed at 10 percent of the airfoil chord. The RANS and LES simulations were then carried out on clean and iced airfoils to compare their performance. The results indicate that the LES predictions are in general more accurate than the RANS model for the flows considered in this study, especially at near stall flight conditions in region where the complex turbulence flows occur. Moreover, the prediction of the reattachment point on the iced airfoil by LES was shown to be fairly accurate at most of flow conditions.