This paper proposes a robust load frequency control (LFC) scheme for a multi-area hybrid power system (HPS) incorporating Interline Power Flow Controllers (IPFCs) and Energy Storage Systems (ESSs). The stochastic nature of renewable generation sources, combined with potential parametric deviations in generation units and network components, necessitates an LFC design that simultaneously addresses multiple conflicting performance objectives. Improving frequency regulation and tie-line power tracking typically demands more aggressive control actions, thereby increasing control effort, while enhanced robustness tends to deteriorate transient response and prolong settling time. To systematically capture these trade-offs, the LFC design is formulated as a multi-objective optimization problem with three competing objectives: minimization of the integral time-weighted absolute error (ITAE), minimization of the H∞-norm of the complementary sensitivity function, and minimization of the control effort. The Strength Pareto Evolutionary Algorithm 2 (SPEA2) is employed to generate a Pareto-optimal set of candidate controllers, and a knee-point selection criterion is applied to identify a representative solution that balances the competing objectives without undue sacrifice of any single criterion. The proposed scheme is validated under parametric uncertainty, variable load disturbances, and model nonlinearities, and its superiority is demonstrated through comparative analysis with established control approaches.