| Teams 2021 Alsco Uniforms 300 |
|---|
| No. | Team | Driver | Mfg |
|---|---|---|---|
| 0 | JD Motorsports | Jeffrey Earnhardt | Chevrolet |
| 1 | JR Motorsports | Michael Annett | Chevrolet |
| 2 | Our Motorsports | Brett Moffitt | Chevrolet |
| 2 | Richard Childress Racing | Myatt Snider | Chevrolet |
| 4 | JD Motorsports | Ryan Vargas | Chevrolet |
| 5 | BJ McLeod Motorsports | Matt Mills | Chevrolet |
| 6 | JD Motorsports | Landon Cassill | Chevrolet |
| 7 | JR Motorsports | Justin Allgaier | Chevrolet |
| 8 | JR Motorsports | Josh Berry | Chevrolet |
| 9 | JR Motorsports | Noah Gragson | Chevrolet |
| 10 | Kaulig Racing | Jeb Burton | Chevrolet |
| 11 | Kaulig Racing | Justin Haley | Chevrolet |
| 13 | MBM Motorsports / Garage 66 | Chad Finchum | Toyota |
| 15 | JD Motorsports | Colby Howard | Chevrolet |
| 16 | Kaulig Racing | AJ Allmendinger | Chevrolet |
| 17 | Rick Ware Racing | Cody Ware | Toyota |
| 18 | Joe Gibbs Racing | Daniel Hemric | Toyota |
| 19 | Joe Gibbs Racing | Brandon Jones | Toyota |
| 20 | Joe Gibbs Racing | Harrison Burton | Toyota |
| 22 | Team Penske | Austin Cindric | Ford |
| 23 | Our Motorsports | Ty Dillon | Chevrolet |
| 26 | Sam Hunt Racing | Grant Enfinger | Toyota |
| 31 | Jordan Anderson Racing | Tyler Reddick | Chevrolet |
| 36 | DGM Racing | Alex Labbé | Chevrolet |
| 39 | RSS Racing | Ryan Sieg | Ford |
| 44 | Alpha Prime Motorsports | Tommy Joe Martins | Chevrolet |
| 48 | Big Machines Racing | Jade Buford | Chevrolet |
| 51 | Jeremy Clements Racing | Jeremy Clements | Chevrolet |
| 54 | Joe Gibbs Racing | Ty Gibbs | Toyota |
| 66 | MBM Motorsports / Garage 66 | Timmy Hill | Toyota |
| 68 | Brandonbilt Motorsports | Brandon Brown | Chevrolet |
| 76 | BJ McLeod Motorsports | Stefan Parsons | Chevrolet |
| 78 | BJ McLeod Motorsports | Jesse Little | Toyota |
| 92 | DGM Racing | Josh Williams | Chevrolet |
| 98 | Stewart Haas Racing | Riley Herbst | Ford |
| 99 | BJ McLeod Motorsports | Chase Briscoe | Ford |