John Darby is an American motor racing official, currently serving as Managing Director of Competition Director of NASCAR. In this capacity, oversees the competition directors of the NASCAR Cup Series (a position Darby previously held), the Xfinity Series, and the Camping World Truck Series. In his position, he is in charge of the officials in each series who usually determine penalties to be imposed for infractions by drivers and crews. He is still competition director for Sprint Cup until a replacement is found.