Coupling graphene’s excellent electron and spin transport properties with a higher spin–orbit coupling (SOC) material allows tackling the hurdle of spin manipulation in graphene due to the proximity to van der Waals layers. Here, we use magneto-transport measurements to study the electron spin resonance on a combined system of graphene and MoS2 at 1.5 K. The electron spin resonance measurements are performed in the frequency range of 18–33 GHz, which allows us to determine the g-factor in the system. We measure the average g-factor of 1.91 for our hybrid system, which is a considerable shift compared to that observed in graphene on SiO2. This is a clear indication of proximity induced SOC in graphene in accordance with theoretical predictions.