The 2008 Indy Japan 300 was the third round of the 2008 IndyCar Series season, for drivers who competed in the series in 2007 and teams that had entered for 2008 who were not former Champ Car teams that were in transition. This was because the 2008 Toyota Grand Prix of Long Beach occurred on the same weekend and there was no way of changing dates to avoid the clash when the reunification took place. Originally scheduled for the afternoon of April 19, 2008 at the 1.52miles Twin Ring Motegi in Motegi, Tochigi, the race was delayed by 22 hours until the morning of April 20, due to water seeping up onto the track from previous heavy rains.[1] Danica Patrick won the race, becoming the first female winner in the history of top-level American open-wheel racing.[2]
Due to rain in the Tochigi region, qualifying was cancelled and the field was set by driver points.[3] Thus, the grid was:
| Pos | No. | Driver | Team | |
|---|---|---|---|---|
| 1 | 3 |  Hélio Castroneves | Penske Racing | |
| 2 | 9 |  Scott Dixon | Chip Ganassi Racing | |
| 3 | 11 | Tony Kanaan | Andretti Green Racing | |
| 4 | 26 |  Marco Andretti | Andretti Green Racing | |
| 5 | 10 | Dan Wheldon | Chip Ganassi Racing | |
| 6 | 7 | Danica Patrick | Andretti Green Racing | |
| 7 | 20 | Ed Carpenter | Vision Racing | |
| 8 | 2 | A. J. Foyt IV | Vision Racing | |
| 9 | 27 |  Hideki Mutoh (R) | Andretti Green Racing | |
| 10 | 17 | Ryan Hunter-Reay | Rahal Letterman Racing | |
| 11 | 15 | Buddy Rice | Dreyer & Reinbold Racing | |
| 12 | 14 | Darren Manning | A. J. Foyt Enterprises | |
| 13 | 4 | Vítor Meira | Panther Racing | |
| 14 | 24 | Jay Howard (R) | Roth Racing | |
| 15 | 6 |  Ryan Briscoe | Penske Racing | |
| 16 | 23 | Townsend Bell | Dreyer & Reinbold Racing | |
| 17 | 25 |  Marty Roth | Roth Racing | |
| 18 | 77 | CURB/Agajanian/Beck Motorsports |
The race's average speed was 164.258mi/h and it featured five lead changes between four drivers, as well as cautions on four for 29 laps.
| Finish | Car No. | Driver | Team | Laps | Time/Retired | Grid | Laps Led | Points | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 7 | Danica Patrick | Andretti Green Racing | 200 | 1:51:02.6739 | 6 | 3 | 50 | |
| 2 | 3 | Hélio Castroneves | Penske Racing | 200 | +5.8594 | 1 | 94 | 40 | |
| 3 | 9 | Scott Dixon | Target Chip Ganassi | 200 | +10.0559 | 2 | 101 | 38 | |
| 4 | 10 | Dan Wheldon | Target Chip Ganassi | 200 | +13.1116 | 5 | 2 | 32 | |
| 5 | 11 | Tony Kanaan | Andretti Green Racing | 200 | +16.0731 | 3 | 0 | 30 | |
| 6 | 20 | Ed Carpenter | Vision Racing | 200 | +16.2872 | 7 | 0 | 28 | |
| 7 | 17 | Ryan Hunter-Reay (R) | Rahal Letterman Racing | 200 | +17.5193 | 10 | 0 | 26 | |
| 8 | 14 | Darren Manning | A. J. Foyt Enterprises | 199 | +1 Lap | 12 | 0 | 24 | |
| 9 | 6 | Ryan Briscoe | Penske Racing | 199 | +1 Lap | 15 | 0 | 22 | |
| 10 | 23 | Townsend Bell | Dreyer & Reinbold Racing | 199 | +1 Lap | 16 | 0 | 20 | |
| 11 | 27 | Hideki Mutoh (R) | Andretti Green Racing | 199 | +1 Lap | 9 | 0 | 19 | |
| 12 | 15 | Buddy Rice | Dreyer & Reinbold Racing | 198 | +2 Laps | 11 | 0 | 18 | |
| 13 | 24 | Jay Howard | Roth Racing | 192 | +8 Laps | 14 | 0 | 17 | |
| 14 | 77 | CURB/Agajanian/Beck Motorsports | 134 | Brakes | 18 | 0 | 16 | ||
| 15 | 2 | A. J. Foyt IV | Vision Racing | 103 | Accident | 8 | 0 | 15 | |
| 16 | 4 | Vítor Meira | Panther Racing | 92 | Accident | 13 | 0 | 14 | |
| 17 | 25 | Marty Roth | Roth Racing | 44 | Accident | 17 | 0 | 13 | |
| 18 | 26 | Marco Andretti | Andretti Green Racing | 0 | Collision | 4 | 0 | 12 |