The 2021 Dead On Tools 250 was a NASCAR Xfinity Series race that was held on October 30, 2021, at the Martinsville Speedway in Martinsville, Virginia. Contested over 250 laps on the 0.526 mi (0.847 km) oval, it was the 32nd race of the 2021 NASCAR Xfinity Series season, the sixth race of the Playoffs, and the final race of the Round of 8. JR Motorsports driver Noah Gragson, in a must-win situation to advance to the Round of 4, collected his third win of the season.

Martinsville Speedway is a NASCAR-owned stock car racing track located in Henry County, in Ridgeway, Virginia, just to the south of Martinsville. At 0.526 miles (0.847 km) in length, it is the shortest track in the NASCAR Xfinity Series. The track was also one of the first paved oval tracks in NASCAR, being built in 1947 by H. Clay Earles. It is also the only remaining race track that has been on the NASCAR circuit from its beginning in 1948.

Austin Cindric was awarded the pole for the race as determined by competition-based formula. Timmy Hill did not have enough points to qualify for the race.

Stage One Laps: 60

Stage Two Laps: 60

Laps: 130