The 2005 Sonoma 100 was Round 11 of the 2005 Menards IRL Infiniti Pro Series. The event was held at Sonoma Raceway in California, United States on 28 August 2005. Marco Andretti was the race winner.
Sonoma 100 Race Result
| Pos. | No. | Driver | Chassis | Engine | Tire | Laps | Laps Led | Status | Started | Points |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 26 | Marco Andretti | Dallara | Infiniti | Firestone | 30 | 30 | Running | 1 | 53 |
| 2 | 33 | Wade Cunningham | Dallara | Infiniti | Firestone | 30 | 0 | Running | 4 | 40 |
| 3 | 24 | Jeff Simmons | Dallara | Infiniti | Firestone | 30 | 0 | Running | 3 | 35 |
| 4 | 9 | Nick Bussell | Dallara | Infiniti | Firestone | 30 | 0 | Running | 8 | 32 |
| 5 | 19 | Chris Festa | Dallara | Infiniti | Firestone | 30 | 0 | Running | 5 | 30 |
| 6 | 7 | Travis Gregg | Dallara | Infiniti | Firestone | 30 | 0 | Running | 9 | 28 |
| 7 | 4 | Marty Roth | Dallara | Infiniti | Firestone | 30 | 0 | Running | 12 | 26 |
| 8 | 20 | Jay Drake | Dallara | Infiniti | Firestone | 29 | 0 | Running | 10 | 24 |
| 9 | 6 | Jon Herb | Dallara | Infiniti | Firestone | 29 | 0 | Running | 11 | 22 |
| DNF | 22 | Scott Mansell | Dallara | Infiniti | Firestone | 24 | 0 | Mechanical | 7 | 20 |
| 11 | 3 | Bobby Wilson | Dallara | Infiniti | Firestone | 24 | 0 | Running | 2 | 19 |
| DNF | 1 | Jaime Camara | Dallara | Infiniti | Firestone | 4 | 0 | Mechanical | 6 | 18 |
| DNS | 11 | Scott Mayer | Dallara | Infiniti | Firestone | 0 | 0 | Did not start | 13 | 17 |