In this thesis, a genetic algorithm: GA) is employed for shape optimization of hydrofoils for application in a sailing craft. The hydrofoil for a sailing craft should have high lift at lower speeds and low drag at higher speeds. Computations are performed for a hydrofoil in deep water as well as one close to the free surface. The commercially available software FLUENT is used for calculation of the flow field, and the software GAMBIT is used for the geometry and mesh generation. Volume of Fluid: VOF) method in FLUENT is employed to define the air/water interface. Genetic algorithm is implemented with GAMBIT and FLUENT for shape optimization of hydrofoils. Maximization of lift to drag ratio is used as the optimization criteria. Optimized shapes are obtained for a hydrofoil in deep water at Re = 10 x 106 and Re = 20 x 106 at angles of attack of 0, 2, 4, and 6 degrees. Optimized shapes are also obtained for a hydrofoil near a free surface at d/c = 0.5 where d is the depth under the free surface and c is the chord length of the hydrofoil. It is shown that GA optimization technique is capable of accurately and efficiently finding the globally optimum hydrofoils.