| Car No. | Driver | Team | Engine | Rounds |
|---|---|---|---|---|
| 1 | JR Hildebrand | AJ Foyt Racing | Chevy | Indy 500 |
| 2 | Josef Newgarden | Team Penske | Chevy | Full Season |
| 3 | Scott McLaughlin | Team Penske | Chevy | Full Season |
| 4 | Dalton Kellett | AJ Foyt Racing | Chevy | Full Season |
| 5 | Pato O'Ward | Arrow McLaren SP | Chevy | Full Season |
| 06 | Helio Castroneves | Meyer Shank Racing | Honda | Six Races |
| 7 | Oliver Askew | Arrow McLaren SP | Chevy | Belle Isle Race 2 |
| 7 | Kevin Magnussen | Arrow McLaren SP | Chevy | Road America |
| 7 | Felix Rosenqvist | Arrow McLaren SP | Chevy | Full Season |
| 8 | Marcus Ericsson | Chip Ganassi Racing | Honda | Full Season |
| 9 | Scott Dixon | Chip Ganassi Racing | Honda | Full Season |
| 10 | Alex Palou | Chip Ganassi Racing | Honda | Full Season |
| 11 | Charlie Kimball | AJ Foyt Racing | Chevy | GMR GP & Indy 500 |
| 12 | Will Power | Team Penske | Chevy | Full Season |
| 14 | Sebastien Bourdais | AJ Foyt Racing | Chevy | Full Season |
| 15 | Graham Rahal | Rahal Letterman Lanigan Racing | Honda | Full Season |
| 16 | Simona de Silvestro | Paretta Autosport | Chevy | Indy 500 |
| 18 | Ed Jones | Dale Coyne Racing/Vasser-Sullivan | Honda | Full Season |
| 20 | Ed Carpenter | Ed Carpenter Racing | Chevy | Ovals |
| 20 | Conor Daly | Ed Carpenter Racing | Chevy | Road/Street |
| 21 | Oliver Askew | Ed Carpenter Racing | Chevy | Road America |
| 21 | Rinus VeeKay | Ed Carpenter Racing | Chevy | Full Season |
| 22 | Simon Pagenaud | Team Penske | Chevy | Full Season |
| 24 | Sage Karam | Dreyer & Reinbold Racing | Chevy | Indy 500 |
| 25 | Stefan Wilson | Andretti Autosport | Honda | Indy 500 |
| 26 | Colton Herta | Andretti Autosport | Honda | Full Season |
| 27 | Alexander Rossi | Andretti Autosport | Honda | Full Season |
| 28 | Ryan Hunter-Reay | Andretti Autosport | Honda | Full Season |
| 29 | James Hinchcliffe | Andretti Steinbrenner Autosport | Honda | Full Season |
| 30 | Takuma Sato | Rahal Letterman Lanigan Racing | Honda | Full Season |
| 45 | Oliver Askew | Rahal Letterman Lanigan Racing | Honda | POR/LAG/LB |
| 45 | Santino Ferrucci | Rahal Letterman Lanigan Racing | Honda | Multiple Races |
| 45 | Christian Lundgaard | Rahal Letterman Lanigan Racing | Honda | Aug IMS |
| 47 | Conor Daly | Ed Carpenter Racing | Chevy | Indy 500 |
| 48 | Jimmie Johnson | Chip Ganassi Racing | Honda | Road/Street |
| 48 | Tony Kanaan | Chip Ganassi Racing | Honda | Ovals |
| 51 | Romain Grosjean | Dale Coyne Racing/Rick Ware Racing | Honda | Road/Street |
| 51 | Pietro Fittipaldi | Dale Coyne Racing/Rick Ware Racing | Honda | Ovals |
| 52 | Ryan Norman | Dale Coyne Racing/Rick Ware Racing | Honda | Mid-Ohio |
| 52 | Cody Ware | Dale Coyne Racing/Rick Ware Racing | Honda | Multiple Races |
| 59 | Max Chilton | Carlin | Chevy | Road/Street/Indy 500 |
| 59 | Conor Daly | Carlin | Chevy | Texas |
| 59 | TBA | Carlin | Chevy | Gateway |
| 60 | Jack Harvey | Meyer Shank Racing | Honda | Full Season |
| 75 | RC Enerson | Top Gun Racing | Chevy | Indy 500 & IMS RC #2 |
| 77 | Callum Ilott | Juncos Hollinger Racing | Chevy | Portland |
| 86 | Juan Pablo Montoya | Arrow McLaren SP | Chevy | GMR GP & Indy 500 |
| 98 | Marco Andretti | Andretti Autosport/Bryan Herta Autosport/Marco Andretti | Honda | Indy 500 |
| TBA | TBA | Juncos Hollinger Racing | Chevy | POR/LAG/LB |
2021 INDY LIGHTS PRESENTED BY COOPER TIRES
| Car No. | Driver | Team | Rounds |
|---|---|---|---|
| 2 | Sting Ray Robb | Juncos Racing | Full Season |
| 5 | Alex Peroni | Carlin | Full Season |
| 7 | Christian Bogle | Carlin | Full Season |
| 11 | Antonio Serravalle | Pserra Racing | Full Season |
| 17 | Devlin DeFrancesco | Andretti Steinbrenner Autosport | Full Season |
| 24 | Benjamin Pedersen | Global Racing Group w/HMD Motorsports | Full Season |
| 26 | Linus Lundqvist | Global Racing Group w/HMD Motorsports | Full Season |
| 27 | Robert Megennis | Andretti Autosport | Full Season |
| 28 | Kyle Kirkwood | Andretti Autosport | Full Season |
| 51 | Rasmus Lindh | Juncos Racing | Final 3 Weekends |
| 51 | Toby Sowery | Juncos Racing | Full Season |
| 59 | Nikita Lastochkin | HMD Motorsports | Full Season |
| 59 | Manuel Sulaiman | HMD Motorsports | Portland |
| 68 | Danial Frost | Andretti Autosport | Full Season |
| 79 | David Malukas | HMD Motorsports | Full Season |
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