| Race details | |
|---|---|
| Race 4 of 13 in the 2005 Champ Car season | |
 Portland International Raceway Track Layout | |
| Date | June 19, 2005 |
| Official name | G.I. Joe's Presents the Champ Car Grand Prix of Portland |
| Location | Portland International Raceway Portland, Oregon, United States |
| Course | Permanent Road Course 1.964 mi / 3.161 km |
| Distance | 105 laps 206.220 mi / 331.905 km |
| Weather | Sunny and Warm |
| Pole position | |
| Driver | Justin Wilson (RuSPORT) |
| Time | 57.597 |
| Fastest lap | |
| Driver | Sébastien Bourdais (Newman/Haas Racing) |
| Time | 59.923 (on lap 79 of 105) |
| Podium | |
| First | Cristiano da Matta (PKV Racing) |
| Second | Sébastien Bourdais (Newman/Haas Racing) |
| Third | Paul Tracy (Forsythe Championship Racing) |
The 2005 G.I. Joe's Presents the Champ Car Grand Prix of Portland was the fourth round of the 2005 Bridgestone Presents the Champ Car World Series Powered by Ford season, held on June 19, 2005 at the Portland International Raceway in Portland, Oregon. The pole sitter was Justin Wilson and the race was won by Cristiano da Matta. It marked the 12th and final Champ Car victory for the 2002 CART champion. It was also the first career Champ Car pole for Wilson, the first of eight in his American open wheel career.