| Location: | Longchamp Racecourse |
| Winning Horse: | Rainbow Quest |
| Previous: | 1984 |
| Next: | 1986 |
The 1985 Prix de l'Arc de Triomphe was a horse race held at Longchamp on Sunday 6 October 1985. It was the 64th running of the Prix de l'Arc de Triomphe.
The winner was Rainbow Quest, a four-year-old colt trained in Great Britain by Jeremy Tree. The winning jockey was Pat Eddery. Sagace finished first by a neck from Rainbow Quest with Kozana two lengths away in third. After a steward's inquiry and an objection from the rider of the runner-up, the places of the first two horses was reversed.[1]
The winning time was 2m 29.5s.
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| Pos. | Marg. | Horse | Age | Jockey | Trainer (Country) | |
|---|---|---|---|---|---|---|
| 2 | Rainbow Quest | 4 | Pat Eddery | Jeremy Tree (GB) | ||
| 1d | nk | Sagace | 5 | Éric Legrix | Patrick Biancone (FR) | |
| 3 | 2 | Kozana | 3 | Alain Lequeux | Alain de Royer-Dupré (FR) | |
| 4 | nk | Sumayr | 3 | Yves Saint-Martin | Alain de Royer-Dupré (FR) | |
| 5 | 1 | Fitnah | 3 | Freddy Head | Criquette Head (FR) | |
| 6 | 2½ | Balitou | 6 | Dominique Boeuf | Patrick Biancone (FR) | |
| 7 | hd | Don Orazio | 3 | M Jerome | F Jovine (ITY) | |
| 8 | ns | Jupiter Island | 5 | Tony Ives | Clive Brittain (GB) | |
| 9 | 6 | Galla Placidia | 3 | Lester Piggott | André Fabre (FR) | |
| 10 | 1 | Iades | 3 | Cash Asmussen | François Boutin (FR) | |
| 11 | Kiliniski | 3 | Willie Carson | John Dunlop (GB) | ||
| 12 | Badinage | 5 | Henri Samani | Charles Bartholomew (FR) | ||
| 13 | Shernazar | 4 | Walter Swinburn | Michael Stoute (GB) | ||
| 14 | Complice | 4 | Alfred Gibert | L Bates (FR) | ||
| 15 | Heraldiste | 3 | Gerald Mosse | Patrick Biancone (FR) |
Further details of the winner, Rainbow Quest.