Despite the high advances of classical molecular simulation to study bulk phases, classical force fields (FFs) to describe interactions at interfaces are rarely available in the literature. In this study, FFs to describe fluid | solid interfaces are developed by matching forces and energies from ab initio simulation and by using a newly developed genetic algorithm (GA). The interfacial FFs are parameterized to be combined with existing classical bulk FFs. Our procedure is tested on the methanol (CH3OH) | ZnO interface. The results for the forces, energies, and some structural adsorption properties calculated using an own parameterized interfacial FF are comparable with results from ab initio and experimental data. With this, we illustrate the potential of the proposed procedure to yield accurate models for interfacial systems to be combined with available bulk FFs.