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.

The World Rally Championship is an international rallying series owned and governed by the FIA. Inaugurated in 1973, it is the second oldest of the FIA's world championships after Formula One. Each season lasts one calendar year, and separate championship titles are awarded to drivers, co-drivers and manufacturers. There are also two support championships, WRC2 and WRC3, which are contested on the same events and stages as the WRC, but with progressively lower maximum performance and running costs of the cars permitted. Junior WRC is also contested on five events of the World Rally Championship calendar.