In this study, three-dimensional simulations were performed using Ansys Fluent 19R1 to investigate the effect of grid patterns on fin aerodynamic characteristics. Three fin models were designed including square, tri, hexa grid patterns, alongside to be more independently comparative, other parameters consisting of frame dimensions, internal web thickness, chord length, reference area and grid cell area were kept similar between the models. The Mach number 0.7, 1.2, 2.5 corresponding to Subsonic, Transonic and Supersonic regimes were investigated for varying angles of attack from −5 to 15 degrees for each fin model. Three control coefficients, Ca, Cn and Chm were compared and they pointed out that the hexa fin pattern has many advantages over the other two fin patterns.