The 2018 Overton's 300 was the 15th stock car race of the 2018 NASCAR Xfinity Series season and the 18th iteration of the event. The race was held on Saturday, June 30, 2018, in Joliet, Illinois at Chicagoland Speedway, a 1.5 miles (2.4 km) permanent D-shaped oval. The race took the scheduled 200 laps to complete. At race's end, Kyle Larson of Chip Ganassi Racing would come back from the rear of the field to win his tenth career NASCAR Xfinity Series win and his second of his part-time season. To fill out the podium, Kevin Harvick and Cole Custer of Stewart-Haas Racing with Biagi-DenBeste would finish second and third, respectively.