Here is the official starting lineup for the Clean Harbors 100 at Watkins Glen International. August 6, 2021.
| Pos | Car | Driver | Manufacturer | Speed | Time | Behind |
|---|---|---|---|---|---|---|
| 1 | 18 | Ty Gibbs | Toyota | 119.754 | 73.651 | Leader |
| 2 | 20 | Corey Heim | Toyota | 118.329 | 74.538 | -0.887 |
| 3 | 1 | Austin Hill | Toyota | 117.649 | 74.969 | -1.318 |
| 4 | 50 | Carson Hocevar | Chevrolet | 117.337 | 75.168 | -1.517 |
| 5 | 23 | Sam Mayer | Chevrolet | 116.961 | 75.410 | -1.759 |
| 6 | 25 | Brandon Jones | Toyota | 116.702 | 75.577 | -1.926 |
| 7 | 14 | Chase Briscoe | Ford | 116.514 | 75.699 | -2.048 |
| 8 | 30 | Kris Wright | Ford | 115.909 | 76.094 | -2.443 |
| 9 | 2 | Nick Sanchez | Chevrolet | 115.651 | 76.264 | -2.613 |
| 10 | 42 | Tyler Ankrum | Chevrolet | 115.208 | 76.557 | -2.906 |
| 11 | 54 | Riley Herbst | Ford | 115.108 | 76.624 | -2.973 |
| 12 | 17 | Taylor Gray | Ford | 114.815 | 76.819 | -3.168 |
| 13 | 21 | Jack Wood | Chevrolet | 114.164 | 77.257 | -3.606 |
| 14 | 32 | Austin Wayne Self | Chevrolet | 113.880 | 77.450 | -3.799 |
| 15 | 46 | Thad Moffitt | Ford | 113.343 | 77.817 | -4.166 |
| 16 | 15 | Drew Dollar | Toyota | 112.925 | 78.105 | -4.454 |
| 17 | 3 | Dale Quarterly | Chevrolet | 112.468 | 78.422 | -4.771 |
| 18 | 28 | Kyle Sieg | Chevrolet | 111.253 | 79.279 | -5.628 |
| 19 | 10 | Amout Kok | Toyota | 108.952 | 80.953 | -7.302 |
| 20 | 74 | Chris Werth | Ford | 108.761 | 81.095 | -7.444 |
| 21 | 27 | Tim Richmond | Toyota | 107.988 | 81.676 | -8.025 |
| 22 | 69 | Russ Lane | Ford | 107.510 | 82.039 | -8.388 |
| 23 | 11 | Ed Pompa | ? | 105.049 | 83.961 | -10.310 |
| 24 | 60 | Brad Perez | Chevrolet | 90.952 | 96.974 | -23.323 |
| 25 | 01 | D.L. Wilson | Toyota | 86.424 | 102.055 | -28.404 |
| 26 | 48 | Brad Smith | Chevrolet | 85.682 | 102.939 | -29.288 |
| 27 | 73 | Andy Jankowiak | Chevrolet | 28.540 | 309.040 | -3:55.389 |
| 28 | 77 | Dr. Ed Bull | Ford | 0.000 | 0.000 | -0.000 |
| 29 | 12 | Tony Cosentino | Toyota | 0.000 | 0.000 | -0.000 |
