Development of large-scale off-shore wind farms (OWFs) around the world has created different technical and economic challenges. Optimal configuration of the electrical interconnection of the OWFs is a key factor to minimize the investment and operational costs. This paper proposes an optimization formulation by using a Genetic Algorithm (GA) to find the optimal electrical interconnection configuration for a given OWF topology with different number of turbines. A search algorithm has been incorporated into the objective function that enumerates all feasible power flow directions from all turbines towards the power collecting hub, identifying the power flow path that minimizes the cable dimensions and thus the overall cost. The algorithm has been tested on several OWF topologies. The impact of the location of the hub has also been investigated by way of simulations. Furthermore, a comparison between single-hub and multi-hub solution has been made for multi-OWF system. The results show that multi-hub solution can be a better choice in general, especially when only the interconnection cost is compared.