The 2018 WeatherTech Raceway California 8 Hours was the second edition of the WeatherTech Raceway California 8 Hours race held on WeatherTech Raceway Laguna Seca on 28 October 2018. The race was contested with GT3-spec cars, GT Cup-spec cars, GT4-spec cars, MARC cars and TCR-touring cars. The race was organized by the Stéphane Ratel Organisation (SRO). The second annual California 8 Hours is the fourth and final round of the 2018 Intercontinental GT Challenge.