The 2018 Rally Mexico was a motor racing event for rally cars that was held over four days between 8 and 11 March 2018. It marked the fifteenth running of Rally Mexico, and was the third round of the 2018 World Rally Championship and its support categories, the WRC-2 and WRC-3 championships. The event was based in the town of León in Guanajuato, and was contested over twenty-two special stages totalling a competitive distance of 344.49 km (214.06 mi).

The 2018 FIA World Rally Championship was the 46th season of the World Rally Championship, a rallying championship recognised by the Fédération Internationale de l'Automobile (FIA) as the highest class of international rallying. Teams and crews were competing in thirteen events—starting with the Monte Carlo Rally in January and finishing with Rally Australia in November—for the World Rally Championships for Drivers, Co-drivers and Manufacturers. Crews were free to compete in cars complying with World Rally Car and Group R regulations; however, only Manufacturers competing with 2017-specification World Rally Cars were eligible to score points in the Manufacturers' championship. The series were once again supported by the World Rally Championship-2 and World Rally Championship-3 categories at every round and by the Junior World Rally Championship at selected rounds.