Most online cell switching solutions are sub-optimal because they are computationally demanding, and thus adapt slowly to a dynamically changing network environments, leading to quality-of-service (QoS) degradation. This makes such solutions impractical for ultra-dense networks (UDN) where the number of base stations (BS) deployed is very large. In this paper, an artificial neural network (ANN) based cell switching solution is developed to learn the optimal switching strategy of BSs in order to minimize the total power consumption of a UDN. The proposed model is first trained offline, after which the trained model is plugged into the network for real-Time decision making. Simulation results reveal that the performance of the proposed solution is very close to the optimal solution in terms of trade-off between the power consumption and QoS. © 2020 IEEE.