The 2005 12 Hours of Sebring was the 53rd running of this event, and took place on March 19, 2005. The race was sponsored by Mobil 1 and was the opening race of the 2005 American Le Mans Series season run by IMSA.
Class winners in bold. Cars failing to complete 70% of winner's distance marked as Not Classified (NC).
| Pos | Class | No | Team | Drivers | Chassis | Tyre | Laps |
|---|---|---|---|---|---|---|---|
| Engine | |||||||
| 1 | LMP1 | 1 | | | Audi R8 | M | 361 |
| Audi 3.6 L Turbo V8 | |||||||
| 2 | LMP1 | 2 | | | Audi R8 | M | 361 |
| Audi 3.6 L Turbo V8 | |||||||
| 3 | LMP1 | 16 | | | MG-Lola EX257 | M | 341 |
| MG (AER) XP20 2.0 L Turbo I4 | |||||||
| 4 | GT1 | 57 | | | Aston Martin DBR9 | M | 338 |
| Aston Martin 6.0 L V12 | |||||||
| 5 | GT1 | 3 | | | Chevrolet Corvette C6.R | M | 337 |
| Chevrolet LS7R 7.0 L V8 | |||||||
| 6 | GT1 | 4 | | | Chevrolet Corvette C6.R | M | 323 |
| Chevrolet LS7R 7.0 L V8 | |||||||
| 7 | GT2 | 31 | | | Porsche 911 GT3-RSR | M | 321 |
| Porsche 3.6 L Flat-6 | |||||||
| 8 | GT1 | 63 | | | Saleen S7-R | M | 318 |
| Ford 7.0 L V8 | |||||||
| 9 | GT1 | 35 | | | Maserati MC12 | P | 316 |
| Maserati 6.0 L V12 | |||||||
| 10 | GT1 | 5 | | | Chevrolet Corvette C5-R | Y | 315 |
| Chevrolet LS7R 7.0 L V8 | |||||||
| 11 | GT2 | 79 | | | Porsche 911 GT3-RSR | P | 314 |
| Porsche 3.6 L Flat-6 | |||||||
| 12 | LMP2 | 10 | | | Courage C65 | K | 311 |
| AER P07 2.0 L Turbo I4 | |||||||
| 13 | GT2 | 45 | | | Porsche 911 GT3-RSR | M | 311 |
| Porsche 3.6 L Flat-6 | |||||||
| 14 | GT1 | 71 | | | Dodge Viper GTS-R | P | 310 |
| Dodge 8.0 L V10 | |||||||
| 15 | GT1 | 58 | | | Aston Martin DBR9 | M | 303 |
| Aston Martin 6.0 L V12 | |||||||
| 16 | GT2 | 66 | | | Porsche 911 GT3-RSR | M | 297 |
| Porsche 3.6 L Flat-6 | |||||||
| 17 | GT2 | 96 | | | Porsche 911 GT3-RSR | D | 278 |
| Porsche 3.6 L Flat-6 | |||||||
| 18 | GT2 | 34 | | | Porsche 911 GT3-R | P | 275 |
| Porsche 3.6 L Flat-6 | |||||||
| 19 DNF | LMP1 | 20 | | | MG-Lola EX257 | M | 264 |
| MG (AER) XP20 2.0L Turbo I4 | |||||||
| 20 NC | GT2 | 51 | | | Panoz Esperante GT-LM | P | 239 |
| Ford (Elan) 5.0 L V8 | |||||||
| 21 DNF | LMP2 | 27 | | | Courage C65 | P | 238 |
| Judd XV675 3.4 L V8 | |||||||
| 22 DNF | GT2 | 43 | | | Porsche 911 GT3-RSR | Y | 207 |
| Porsche 3.6 L Flat-6 | |||||||
| 23 DNF | LMP1 | 12 | | | Riley & Scott Mk III C | D | 202 |
| Elan 6L8 6.0 L V8 | |||||||
| 24 DNF | LMP2 | 37 | | | Lola B05/40 | G | 166 |
| AER P07 2.0 L Turbo I4 | |||||||
| 25 DNF | GT1 | 83 | | | Saleen S7-R | P | 159 |
| Ford 7.0 L V8 | |||||||
| 26 DNF | GT2 | 41 | | | TVR Tuscan T400R | D | 157 |
| TVR Speed Six 4.0 L I6 | |||||||
| 27 DNF | GT1 | 86 | | | Ferrari 550-GTS Maranello | M | 155 |
| Ferrari 5.9 L V12 | |||||||
| 28 DNF | GT2 | 40 | | | TVR Tuscan T400R | D | 136 |
| TVR Speed Six 4.0 L I6 | |||||||
| 29 DNF | LMP1 | 88 | | | Dallara SP1 | M | 130 |
| Nissan 3.6 L Turbo V8 | |||||||
| 30 DNF | GT2 | 50 | | | Panoz Esperante GT-LM | P | 121 |
| Ford (Elan) 5.0 L V8 | |||||||
| 31 DNF | GT2 | 48 | | | Spyker C8 Spyder GT2-R | D | 121 |
| Audi (Mader) 3.8 L V8 | |||||||
| 32 DNF | GT2 | 23 | | | Porsche 911 GT3-RSR | M | 98 |
| Porsche 3.6 L Flat-6 | |||||||
| 33 DNF | LMP2 | 30 | | | Lola B2K/40 | P | 62 |
| Judd XV675 3.4 L V8 | |||||||
| 34 DNF | GT2 | 24 | | | Porsche 911 GT3-RSR | M | 62 |
| Porsche 3.6 L Flat-6 | |||||||
| 35 DNF | GT2 | 44 | | | Porsche 911 GT3-RSR | M | 46 |
| Porsche 3.6 L Flat-6 | |||||||
| 36 DNF | GT2 | 67 | | | Porsche 911 GT3-RSR | M | 21 |
| Porsche 3.6 L Flat-6 | |||||||
| 37 DNF | GT2 | 47 | | | Spyker C8 Spyder GT2-R | D | 18 |
| Audi (Mader) 3.8 L V8 | |||||||
| 38 DNF | LMP2 | 15 | | | Lola B05/40 | P | 11 |
| Nicholson-McLaren 3.3 L V8 |