The 2003 IRL Infiniti Pro Series was the second season of the series under the Indy Racing League ownership, and the 18th in Indy NXT combined history, as officially recognized by IndyCar. All teams used Dallara IL-02 chassis and Infiniti engines.
British rookie Mark Taylor won the series with a total of 7 wins in 12 races, driving for a newly formed program by IndyCar team Panther Racing, who then signed him to drive for the team's main programme in 2004. Taylor's last win at Fontana crowned him as the champion with one race to spare over Indy Lights returnee Jeff Simmons, who won two races at Gateway and Kentucky for another new team, Keith Duesenberg Racing.
The season was notable for the first running of the Freedom 100 at the Indianapolis Motor Speedway, this being the first time that a support race was included in the Indianapolis 500 program. Ed Carpenter, driving for reining champions A. J. Foyt Enterprises, won the race over Cory Witherill from pole position, his lone win of the year in route to a 3rd place finish in the standings. Thiago Medeiros won the final race at Texas and finished a mere six points behind Carpenter.
Aaron Fike was also a winner at Pikes Peak, but he missed the Phoenix race early in the season for a DUI offence and didn't score another podium during the year, losing fifth place in the points to Witherill. Fike still finished ahead of 2002 runner-up Arie Luyendyk Jr., who missed out again on race wins with a best finish of third, and would not win a race in the series until 2008. Among former IndyCar competitors Witherill and Brandon Erwin competed full-time in the series, while Billy Roe, Scott Harrington and Ronnie Johncox also took part in the Freedom 100, and Dave Steele in the Nashville race.
As well as Panther and Duesenberg, Kenn Hardley Racing also joined the field. Luyendyk Racing left the series after the 2002 season, while Roquin Motorsports and Bowes Seal Fast Racing only contested a handful of races and REV1 Racing withdrew after the Freedom 100. The series had at least 13 drivers at each round, with 19 competitors at the Freedom 100 and 17 at the season finale in Texas. However, only seven drivers competed in every race, with three more contesting all but one race.[1]
| Team | Drivers | Rounds | |
|---|---|---|---|
| Brian Stewart Racing | 3 |  Marty Roth | 1–2, 10–12 |
| Jonathan Urlin[2] | 3–7 | ||
| 33 | 1–2 | ||
 Craig Dollansky[3] | 3 | ||
| Dave Steele | 6 | ||
| Marty Roth | 7 | ||
| Paul Dana | 8–11 | ||
| Tony Turco | 12 | ||
| Panther Racing[4] | 4 |  Mark Taylor | All |
| 41 | Dane Carter[5] | 12 | |
| Sinden Racing Service | 5 | Arie Luyendyk Jr.[6] | All |
| Sam Schmidt Motorsports | 6 | Lloyd Mack[7] | 1 |
 Marco Cioci[8] | 3 | ||
| Ross Fonferko[9] | 6–7 | ||
| 9 | Tom Wood[10] | 1–9 | |
| Taylor Fletcher[11] [12] | 10–12 | ||
| 99 | Brandon Erwin[13] | 1–9 | |
| Marco Cioci | 10 | ||
| Brad Pollard[14] | 11–12 | ||
| REV 1 Racing | 8 | Ronnie Johncox | 1–3 |
| Roquin Motorsports | 11 |  Rolando Quintanilla | 12 |
| Bowes Seal Fast Racing | 3 | ||
| 37 | Billy Roe[15] | 3 | |
| Beardsley Motorsports | 12 | Matt Beardsley[16] | 1–7, 11–12 |
| A. J. Foyt Enterprises | 14 | Ed Carpenter[17] | All |
| Keith Duesenberg Racing[18] | 20 | Jeff Simmons[19] | All |
| Kenn Hardley Racing[20] | 24 | Paul Dana[21] | 1–7 |
| Moses Smith[22] | 8 | ||
| Billy Roe[23] | 9–12 | ||
| AFS Racing | 25 | Scott Harrington | 3 |
| G. J. Mennen[24] | 5, 7–12 | ||
| 27 | Gary Peterson | 1–5, 7–12 | |
| Genoa Racing | 36 |  Thiago Medeiros[25] | All |
| Hemelgarn 91/Johnson Motorsports | 91 | Aaron Fike[26] | 1, 3–12 |
| Tony Ave[27] | 2 | ||
| 92 | Cory Witherill | All |
All seven rounds contested in the 2002 season were retained in the schedule, which now supported the IRL IndyCar Series from the beginning of the season and was expanded to 12 races, all held on ovals. For the first time, a racing series would hold a race at the Indianapolis Motor Speedway as a support event for the Indianapolis 500 with the first running of the Freedom 100, followed by the series' first visit to Pikes Peak. New rounds were also added at former Indy Lights venues Homestead-Miami (last featured in 1999), Phoenix (absent since 1995) and California, which hosted the last race of the original Indy Lights series in 2001.
| Rd. | Date | Race name | Track | Location | |
|---|---|---|---|---|---|
| 1 | March 2 | Western Union 100 | Homestead–Miami Speedway | Homestead, Florida | |
| 2 | March 22 | Phoenix 100 | Phoenix International Raceway | Avondale, Arizona | |
| 3 | May 18 | Freedom 100 | Indianapolis Motor Speedway | Speedway, Indiana | |
| 4 | June 14 | Pikes Peak 100 | Pikes Peak International Raceway | Fountain, Colorado | |
| 5 | July 6 | Aventis Racing for Kids 100 | Kansas Speedway | Kansas City, Kansas | |
| 6 | July 18 | Cleanevent 100 | Nashville Superspeedway | Lebanon, Tennessee | |
| 7 | July 27 | Michigan 100 | Michigan International Speedway | Brooklyn, Michigan | |
| 8 | August 9 | St. Louis 100 | Gateway International Raceway | Madison, Illinois | |
| 9 | August 16 | Kentucky 100 | Kentucky Speedway | Sparta, Kentucky | |
| 10 | September 6 | Chicago 100 | Chicagoland Speedway | Joliet, Illinois | |
| 11 | September 20 | California 100 | California Speedway | Fontana, California | |
| 12 | October 11 | dreamerscandles.com 100 | Texas Motor Speedway | Fort Worth, Texas |
| Position | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | 10th | 11th | 12th | 13th | 14th | 15th | 16th | 17th | 18th | 19th |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Points | 50 | 40 | 35 | 32 | 30 | 28 | 26 | 24 | 22 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 |
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