IROC IX
The ninth year of IROC competition took place in 1985. IROC IX saw the use of the Chevrolet Camaro in all races, was the second straight season that television coverage was on CBS, and continued the format introduced in IROC VIII. Race one took place on the Daytona International Speedway, race two took place at Mid-Ohio, race three was rained out at Talladega Superspeedway, and race four concluded the year at Michigan International Speedway. Harry Gant won the championship in a tie-breaker with Darrell Waltrip, and took home $158,200 for his efforts.
The roster of drivers and final points standings were as follows:
| Rank | Driver | Points | Winnings | Series |
| 1 |  Harry Gant 1 | 45 | $158,200 | NASCAR Winston Cup Series 2nd in 1984 Winston Cup points |
| [|2] | Darrell Waltrip 1 | 45 | $80,400 | NASCAR Winston Cup Series 5th in 1984 Winston Cup points |
| [|3] | Bobby Rahal | 40 | $55,100 | CART PPG IndyCar World Series 3rd in 1984 IndyCar points |
| 4 | Tom Sneva | 32 | $43,000 | CART PPG IndyCar World Series 2nd in 1984 IndyCar points |
| 5 |  Terry Labonte 2 | 31 | $39,300 | NASCAR Winston Cup Series 1984 Winston Cup Champion |
| 6 |  Derek Bell 2 | 31 | $30,000 | World Endurance Championship 4th in 1984 World Sportscar Championship |
| 7 | John Watson | 30 | $29,000 | FIA Formula One World Championship World Endurance Championship |
| 8 | Cale Yarborough | 29 | $27,400 | NASCAR Winston Cup Series Defending IROC Champion 1984 Daytona 500 winner |
| 9 | A. J. Foyt | 28 | $29,500 | CART PPG IndyCar World Series IROC III & IROC IV Champion |
| 10 |  Jochen Mass | 27 | $23,000 | World Endurance Championship 2nd in 1984 World Sportscar Championship |
| 11 | Mario Andretti 3 | 25 | $26,700 | CART PPG IndyCar World Series 1984 IndyCar Champion IROC VI champion |
| 12 | Tom Gloy | 13 | $20,000 | SCCA Trans-Am Series 1984 Trans-Am Champion |
Race results
Race One, Daytona International Speedway
Friday, February 15, 1985| Finish | Grid | Car no. | Driver | Car Make | Car Color | Laps | Status | Laps Led | Points |
| 1 | 11 | 5 | Darrell Waltrip | Chevrolet Camaro | Light Blue | 40 | 0:32:55 | 1 | 23 ' |
| 2 | 6 | 1 | Tom Sneva | Chevrolet Camaro | White | 40 | Flagged | 17 | |
| 3 | 9 | 4 | A. J. Foyt | Chevrolet Camaro | Cream | 40 | Flagged | 35 | 19 ' |
| 4 | 4 | 8 | Derek Bell | Chevrolet Camaro | Orange | 40 | Flagged | 12 | |
| 5 | 12 | 7 | Harry Gant | Chevrolet Camaro | 40 | Flagged | 10 | ||
| 6 | 7 | 3 | Cale Yarborough | Chevrolet Camaro | Pink | 40 | Flagged | 4 | 12 ' |
| 7 | 8 | 17 | Jochen Mass | Chevrolet Camaro | Silver | 40 | Flagged | 8 | |
| 8 | 1 | 2 | John Watson | Chevrolet Camaro | 40 | Flagged | 7 | ||
| 9 | 3 | 12 | Bobby Rahal | Chevrolet Camaro | 39 | Crash | 6 | ||
| 10 | 5 | 6 | Terry Labonte | Chevrolet Camaro | Yellow | 39 | Flagged | 5 | |
| 11 | 10 | 11 | Tom Gloy | Chevrolet Camaro | 15 | Crash | 4 | ||
| 12 | 2 | 9 | Mario Andretti | Chevrolet Camaro | Orange Yellow | 5 | Mechanical | 3 |
' Indicates 5 bonus points added to normal race points scored for leading the most laps.
' Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps
' Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps.
Average speed:
Cautions: 1
Margin of victory: 3 sec
Lead changes: 3
Race Two, Mid-Ohio Sports Car Course
Friday, June 8, 1985| Finish | Grid | Car no. | Driver | Car Make | Car Color | Laps | Status | Laps Led | Points |
| 1 | 4 | 17 | Bobby Rahal | Chevrolet Camaro | Silver | 29 | 0:49:30 | 2 | 24 ' |
| 2 | 5 | 7 | John Watson | Chevrolet Camaro | 29 | Flagged | 17 | ||
| 3 | 1 | 3 | Mario Andretti | Chevrolet Camaro | Pink | 29 | Flagged | 27 | 19 ' |
| 4 | 6 | 8 | Jochen Mass | Chevrolet Camaro | Orange | 29 | Flagged | 12 | |
| 5 | 9 | 2 | Derek Bell | Chevrolet Camaro | 29 | Flagged | 10 | ||
| 6 | 8 | 1 | Harry Gant | Chevrolet Camaro | White | 29 | Flagged | 9 | |
| 7 | 12 | 6 | Darrell Waltrip | Chevrolet Camaro | Yellow | 29 | Flagged | 8 | |
| 8 | 11 | 11 | Tom Sneva | Chevrolet Camaro | 29 | Flagged | 7 | ||
| 9 | 3 | 5 | Terry Labonte | Chevrolet Camaro | Powder Blue | 29 | Flagged | 6 | |
| 10 | 10 | 10 | A. J. Foyt | Chevrolet Camaro | 29 | Flagged | 5 | ||
| 11 | 2 | 18 | Tom Gloy | Chevrolet Camaro | Light Blue | 29 | Flagged | 4 | |
| 12 | 7 | 12 | Cale Yarborough | Chevrolet Camaro | 29 | Flagged | 3 |
' Indicates 5 bonus points added to normal race points scored for leading the most laps.
' Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps
Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps.
Average speed:
Cautions: none
Margin of victory: 2.4 sec
Lead changes: 1
Race Three, Talladega Superspeedway
This race was scheduled for Saturday May 4th, 1985 but was canceled due to rainRace Four, Michigan International Speedway
Saturday, August 10, 1985| Finish | Grid | Car no. | Driver | Car Make | Car Color | Laps | Status | Laps Led | Points |
| 1 | 8 | 18 | Harry Gant | Chevrolet Camaro | Light Blue | 50 | 0:39:09 | 33 | 26 ' |
| 2 | 10 | 5 | Terry Labonte | Chevrolet Camaro | Powder Blue | 50 | Flagged | 13 | 20 ' |
| 3 | 9 | 12 | Cale Yarborough | Chevrolet Camaro | 50 | Flagged | 14 | ||
| 4 | 1 | 2 | Darrell Waltrip | Chevrolet Camaro | 50 | Flagged | 4 | 14 ' | |
| 5 | 2 | 1 | Bobby Rahal | Chevrolet Camaro | White | 50 | Flagged | 10 | |
| 6 | 6 | 11 | Derek Bell | Chevrolet Camaro | 50 | Flagged | 9 | ||
| 7 | 3 | 6 | Tom Sneva | Chevrolet Camaro | Yellow | 50 | Flagged | 8 | |
| 8 | 7 | 17 | Jochen Mass | Chevrolet Camaro | Silver | 50 | Flagged | 7 | |
| 9 | 4 | 8 | John Watson | Chevrolet Camaro | Orange | 50 | Flagged | 6 | |
| 10 | 11 | 3 | Tom Gloy | Chevrolet Camaro | Pink | 49 | Flagged | 5 | |
| 11 | 5 | 7 | A. J. Foyt | Chevrolet Camaro | 27 | Mechanical | 4 | ||
| 12 | X | X | Mario Andretti 3 | Chevrolet Camaro | Not Assigned | 0 | Did Not Start, Injured | 3 |
' Indicates 5 bonus points added to normal race points scored for leading the most laps.
' Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps
' Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps.
Average speed:
Cautions: none
Margin of victory: 4 feet
Lead changes: 8