The 2018 Roseanne 300 was the 5th stock car race of the 2018 NASCAR Xfinity Series season, and the 20th iteration of the event. The race was held on Saturday, March 17, 2018, in Fontana, California, at Auto Club Speedway, a 2 miles (3.2 km) permanent D-shaped oval racetrack. The race took the scheduled 150 laps to complete. At race's end, Joey Logano of Team Penske would dominate and win his 29th NASCAR Xfinity Series win of his career and the first of his part-time season. To fill out the podium, Justin Allgaier and Elliott Sadler, both driving for JR Motorsports would finish second and third, respectively.