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 |  ADT Champion Racing |  JJ Lehto Marco WernerTom Kristensen | Audi R8 | 361 | ||
| Audi 3.6 L Turbo V8 | ||||||||
| 2 | LMP1 | 2 | ADT Champion Racing |  Emanuele Pirro Frank Biela Allan McNish | Audi R8 | 361 | ||
| Audi 3.6 L Turbo V8 | ||||||||
| 3 | LMP1 | 16 | Dyson Racing | James Weaver Andy Wallace Butch Leitzinger | MG-Lola EX257 | 341 | ||
| MG (AER) XP20 2.0 L Turbo I4 | ||||||||
| 4 | GT1 | 57 | Aston Martin Racing | Darren Turner David Brabham Stéphane Ortelli | Aston Martin DBR9 | 338 | ||
| Aston Martin 6.0 L V12 | ||||||||
| 5 | GT1 | 3 | Corvette Racing |  Ron Fellows Johnny O'Connell Max Papis | Chevrolet Corvette C6.R | 337 | ||
| Chevrolet LS7R 7.0 L V8 | ||||||||
| 6 | GT1 | 4 | Corvette Racing | Oliver Gavin Olivier Beretta Jan Magnussen | Chevrolet Corvette C6.R | 323 | ||
| Chevrolet LS7R 7.0 L V8 | ||||||||
| 7 | GT2 | 31 | Petersen Motorsports White Lightning Racing | Lucas Luhr Jörg Bergmeister Patrick Long | Porsche 911 GT3-RSR | 321 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 8 | GT1 | 63 | ACEMCO Motorsports | Johnny Mowlem Terry Borcheller Ralf Kelleners | Saleen S7-R | 318 | ||
| Ford 7.0 L V8 | ||||||||
| 9 | GT1 | 35 | Maserati Corse Risi Competizione | Andrea Bertolini Fabio Babini Fabrizio de Simone | Maserati MC12 | 316 | ||
| Maserati 6.0 L V12 | ||||||||
| 10 | GT1 | 5 | Pacific Coast Motorsports | Ryan Dalziel Alex Figge David Empringham | Chevrolet Corvette C5-R | 315 | ||
| Chevrolet LS7R 7.0 L V8 | ||||||||
| 11 | GT2 | 79 | J3 Racing | Tim Sugden Niclas Jönsson | Porsche 911 GT3-RSR | 314 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 12 | LMP2 | 10 | Miracle Motorsports | Jeff Bucknum Chris McMurry Ian James | Courage C65 | 311 | ||
| AER P07 2.0 L Turbo I4 | ||||||||
| 13 | GT2 | 45 | Flying Lizard Motorsports | Jon Fogarty Johannes van Overbeek Darren Law | Porsche 911 GT3-RSR | 311 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 14 | GT1 | 71 | Carsport America |  Jean-Philippe Belloc Michele Rugolo Tom Weickardt | Dodge Viper GTS-R | 310 | ||
| Dodge 8.0 L V10 | ||||||||
| 15 | GT1 | 58 | Aston Martin Racing |  Peter Kox Pedro Lamy Stéphane Sarrazin | Aston Martin DBR9 | 303 | ||
| Aston Martin 6.0 L V12 | ||||||||
| 16 | GT2 | 66 | TRG | Tracy Krohn Michael Cawley Marc Sluszny | Porsche 911 GT3-RSR | 297 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 17 | GT2 | 96 | IN2 Racing | Michael Vergers Juan Barazi Andrew Thompson | Porsche 911 GT3-RSR | 278 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 18 | GT2 | 34 | ZIP Racing | Spencer Pumpelly Andy Lally Steven Ivankovich | Porsche 911 GT3-R | 275 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 19 DNF | LMP1 | 20 | Dyson Racing | Chris Dyson Guy Smith | MG-Lola EX257 | 264 | ||
| MG (AER) XP20 2.0L Turbo I4 | ||||||||
| 20 NC | GT2 | 51 | Panoz Motor Sports | Gunnar Jeannette Bryan Sellers Scott Maxwell | Panoz Esperante GT-LM | 239 | ||
| Ford (Elan) 5.0 L V8 | ||||||||
| 21 DNF | LMP2 | 27 | Kruse Motorsport | Ian Mitchell Phillip Bennett Harold Primat | Courage C65 | 238 | ||
| Judd XV675 3.4 L V8 | ||||||||
| 22 DNF | GT2 | 43 | BAM | Mike Rockenfeller Martin Jensen Tony Burgess | Porsche 911 GT3-RSR | 207 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 23 DNF | LMP1 | 12 | Autocon Motorsports | Michael Lewis Tomy Drissi Bryan Willman | Riley & Scott Mk III C | 202 | ||
| Elan 6L8 6.0 L V8 | ||||||||
| 24 DNF | LMP2 | 37 | Telesis Intersport Racing | Jon Field Duncan Dayton Gregor Fisken | Lola B05/40 | 166 | ||
| AER P07 2.0 L Turbo I4 | ||||||||
| 25 DNF | GT1 | 83 | Graham Nash Motorsport | Nigel Smith Ricky Cole Rick Sutherland | Saleen S7-R | 159 | ||
| Ford 7.0 L V8 | ||||||||
| 26 DNF | GT2 | 41 | Team LNT | Richard Dean Patrick Pearce Marc Hynes | TVR Tuscan T400R | 157 | ||
| TVR Speed Six 4.0 L I6 | ||||||||
| 27 DNF | GT1 | 86 | Larbre Compétition | Christophe Bouchut Fabrizio Gollin Sébastien Bourdais | Ferrari 550-GTS Maranello | 155 | ||
| Ferrari 5.9 L V12 | ||||||||
| 28 DNF | GT2 | 40 | Team LNT | Jonny Kane Warren Hughes Lawrence Tomlinson | TVR Tuscan T400R | 136 | ||
| TVR Speed Six 4.0 L I6 | ||||||||
| 29 DNF | LMP1 | 88 | Rollcentre Racing | João Barbosa Didier Theys Michael Krumm | Dallara SP1 | 130 | ||
| Nissan 3.6 L Turbo V8 | ||||||||
| 30 DNF | GT2 | 50 | Panoz Motor Sports | Bill Auberlen Robin Liddell Emanuele Naspetti | Panoz Esperante GT-LM | 121 | ||
| Ford (Elan) 5.0 L V8 | ||||||||
| 31 DNF | GT2 | 48 | Spyker Squadron | Tom Coronel Donny Crevels Marc Goossens | Spyker C8 Spyder GT2-R | 121 | ||
| Audi (Mader) 3.8 L V8 | ||||||||
| 32 DNF | GT2 | 23 | Alex Job Racing | Timo Bernhard Sascha Maassen Romain Dumas | Porsche 911 GT3-RSR | 98 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 33 DNF | LMP2 | 30 | Telesis Intersport Racing | Clint Field Liz Halliday Gareth Ridpath | Lola B2K/40 | 62 | ||
| Judd XV675 3.4 L V8 | ||||||||
| 34 DNF | GT2 | 24 | Alex Job Racing | Randy Pobst Ian Baas Brian Cunningham | Porsche 911 GT3-RSR | 62 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 35 DNF | GT2 | 44 | Flying Lizard Motorsports | Lonnie Pechnik David Murry Seth Neiman | Porsche 911 GT3-RSR | 46 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 36 DNF | GT2 | 67 | TRG | Pierre Ehret Kevin Buckler Andrew Davis | Porsche 911 GT3-RSR | 21 | ||
| Porsche 3.6 L Flat-6 | ||||||||
| 37 DNF | GT2 | 47 | Spyker Squadron | Peter van Merksteijn Frans Munsterhuis Marino Franchitti | Spyker C8 Spyder GT2-R | 18 | ||
| Audi (Mader) 3.8 L V8 | ||||||||
| 38 DNF | LMP2 | 15 | Binnie Motorsports | William Binnie Robert Julien Adam Sharpe | Lola B05/40 | 11 | ||
| Nicholson-McLaren 3.3 L V8 |