| 2004 Infiniti Pro Series season | |
|---|---|
| Infiniti Pro Series | |
| Season | |
| Races | 12 |
| Start date | February 29 |
| End date | October 16 |
| Awards | |
| Drivers' champion |  Thiago Medeiros |
| Teams' champion |  Sam Schmidt Motorsports |
| Rookie of the Year | P. J. Chesson |
The 2004 Menards IRL Infiniti Pro Series season was the third season of the series under the Indy Racing League ownership, and the 19th in Indy NXT combined history, as officially recognized by IndyCar. All teams used Dallara IL-02 chassis and Infiniti engines.
In his second year of Pro Series competition, Thiago Medeiros won the championship convincingly, giving Sam Schmidt Motorsports its first title. He won six wins, including the second running of the Freedom 100 from pole position, scored seven pole positions and led the most laps in all but two of the 12 races. Medeiros became champion by taking the green flag at the penultimate round in Chicagoland, and finished with a 134-point lead over Paul Dana, who scored his lone Infiniti Pro Series win at Milwaukee.
Despite joining the Infiniti Pro Series at the fourth round in Kansas, rookie P. J. Chesson rallied to a fourth place in the standings, including a three-win streak with newcomers Mo Nunn Racing, an effort instigated and managed by Nunn's wife Kathryn. Despite a penalty at the last round that demoted him behind Arie Luyendyk Jr. in the standings, Chesson won Rookie of the Year over Leonardo Maia by 25 points.
A. J. Foyt Enterprises and Panther Racing, the champions of the previous two editions, left the series, although Foyt entered a car for Jeff Simmons at the Freedom 100, finishing second behind Medeiros. Simmons and Marty Roth became the first drivers to contest the Indianapolis 500 and the Freedom 100 in the same year. Sinden Racing Service and Genoa Racing also left the series entirely, while the privateer effort by Matt Beardsley ceased to be after the Freedom 100. On the other hand, Roquin Motorsports re-expanded to a full time effort, Roth Racing, Racing Professionals and Bullet-Team Motorsports made their debut with partial seasons, apart from Mo Nunn joining the championship at the fourth round.
While the Freedom 100 attracted 17 competitors, the Infiniti Pro Series struggled with entries throughout much of 2004, especially during the summer stretch, with only nine cars and just three finishers at the Milwaukee round. Grid sizes improved over the last three races, with 15 drivers in each round. Only the top 3 drivers in the standings contested the full season, with two others missing one round. Former IndyCar drivers that competed during the season were Billy Roe, Jon Herb, Cory Witherill and Scott Mayer.