A hydrocarbon resource recovery system may include an RF source, and an RF antenna assembly coupled to the RF source and extending laterally within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly may include first and second tubular conductors, and a dielectric isolator coupled between the first and second tubular conductors to define a dipole antenna. The hydrocarbon resource recovery system may include solvent injectors within respective laterally extending wellbores extending transverse and above the RF antenna assembly and configured to selectively inject solvent into the subterranean formation adjacent the RF antenna assembly.