This paper presents a novel Hinfin robust controller for resonant converters. The proposed approach employs a simplified, accurate and simple MIMO model of the converter to design the controller. The controller exhibits tight output voltage regulation characteristics that is robust against system parameter variations. Results obtained from a 3 KW prototype system operating at 120 KHz validate the feasibility of the proposed scheme and exhibit its excellent performance. The experimental results demonstrate that 0.02% voltage regulation is achieved using the proposed Hinfin control technique.