This article explores predictor-based fractional-order sliding mode load frequency control for interconnected power systems, accounting for input delay. First, a predictor-based method is developed to deal with the input delay. By designing a predictor to accurately predict the future state, the delayed control input can be replaced by the delay-free control input. Then, a novel fractional-order sliding mode controller is designed, where the predictor is used rather than the system state, reducing the dependence on directly measurable system states and enhancing the dynamic response of the system. Furthermore, a disturbance observer is designed to estimate the disturbance, allowing the controller to correspondingly compensate for it, and the robustness of the system is improved. Finally, three cases are conducted to show the validity of the presented method.