The 2018 DC Solar 200 was the fourth stock car race of the 2018 NASCAR Xfinity Series season and the 14th iteration of the event. The race was held on Saturday, March 10, 2018 in Avondale, Arizona, at ISM Raceway, a 1 mile (1.6 km) permanent low-banked tri-oval race track. The race took the scheduled 200 laps to complete. At race's end, Brad Keselowski of Team Penske would take control after the final pit stops to overcome a penalty and win his 37th career NASCAR Xfinity Series season and his first of his part-time season. To fill out the podium, Justin Allgaier of JR Motorsports and Kyle Busch of Joe Gibbs Racing would finish second and third, respectively.