Wing-in-Ground (WIG) effect aircraft have become an interesting concept in the context of reducing the environmental footprint and increasing the speed of coastal transport. However, obtaining an efficient wing shape in a cost-effective manner is an elusive goal in the early stages of any aircraft design. In this work, a multi-objective wing planform optimisation methodology is proposed by combining a parametric shape modeller OpenVSP, a low fidelity solver VSPAERO and Non-dominated Sorting Genetic Algorithm (NSGA-II) to support the preliminary design of wing-in-ground effect aircraft. Methodology is demonstrated by performing three different wing planform optimisations ranging from planar wing optimisation to nonplanar wingtip optimisation by improving both lift to drag ratio and static height stability characteristics of a wing planform in ground effect. The analysis of the Pareto optimal solutions suggests that when employing the Vortex Lattice Method (VLM) for aerodynamics and stability derivatives computation, the optimiser converged to drooped wing type configuration which enhances both aerodynamic efficiency and static height stability characteristics of wing-alone configuration.