© 2022, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.Recently, with the advances in modern missile industry, faster and more maneuverable missiles became fashionable. Designing fast and agile missiles requires efficient and strong control surfaces and grid fin is a candidate to fulfill this need. Grid fins are unconventional control surfaces, which has an outer frame supporting interior web structure. In this paper, “MICOM Grid Fin” wind tunnel experiments are used as the test case to validate the CFD analysis. To perform a parametric study, several grid fin geometries are investigated at Mach number of 2.5 and four different angles of attack ranging from 0° to 15° and two roll angles of 0° and 45°. A parametric design study is performed with chord, span, width, gap between members, web thickness and frame thickness parameters using Box-Behnken DOE methodology. The objective of this study is to create and validate response surfaces for grid fin aerodynamic coefficients using the CFD results. Good agreement is achieved estimating the aerodynamic coefficients with response surfaces except the pitch moment coefficient. Flow field investigations showed that separated flow is occurred at 15° angle of attack resulting in moderate agreement in pitch moment.