Boundary layer flow separation from the wing surface plays important role for the airfoil drag development, and therefore the flow separation must be controlled properly. Additionally, three-dimensional flow separation at the near-wall contributes significantly to the increase in the drag. One method that can be used to control flow separation is the installation of vortex generator. This study is intended to investigate the effect of the vortex generator on the airfoil to modify the flow separation and thus on the airfoil characteristics, including drag and lift. Additionally, the total pressure loss is also evaluated at this study. This study is performed numerically using Ansys Fluent to evaluate the effect of the vortex generator attached on the NASA LS-0417 airfoil on its aerodynamic characteristics. The vortex generator is having rectangular form with length, height and thickness are, respectively, 5.0, 2.4, and 0.5 mm. The vortex generators are located at streamwise positions x/c = 0.45, 0.50, and 0.55, and at spanwise positions z/c = 0.004 and 0.006. The Reynolds number is 1 × 105 based on the freestream velocity and the airfoil chord length, where the chord length (c) is 100 mm. The airfoil span (s) is 500 mm. Three-dimensional simulation using k–ω SST turbulent model was employed. The results of the present study show that the vortex generator can modify the flow separation significantly, and it can modify airfoil drag and lift. At the present study, the placement of vortex generator at x/c = 0.45 and z/c = 0.004 results in the best improvement compared to the other placements, where at this VG placement, the lift to drag ratio increases by approximately 7.3% compared to that of the plain airfoil counterpart. Finally, the reduction of the total pressure loss up to approximately of 28.5% can also be reported at the aforementioned vortex generator placement.