Which Irish Horses Are Running in the Prix de l’Arc 2026?

Prix de l’Arc de Triomphe 2026 Irish runners give this year’s race a distinctly Ballydoyle flavour. Aidan O’Brien sends three to ParisLongchamp, led by Diamond Necklace, while Joseph O’Brien relies on Thundering On. The final field has 16 runners, with the draw now known ahead of Sunday’s 15:05 Irish-time start. Our Irish horse racing betting guide is the natural place to compare prices and terms.

Which Irish runners are in the 2026 Arc?

Four Irish-trained runners have made the final field. Aidan O’Brien is responsible for three of them, while Joseph O’Brien supplies the fourth.

The draw immediately creates two different stories. Benvenuto Cellini has the inside stall, while Diamond Necklace must work from the widest gate in the race. It does not decide the Arc, but it changes the tactical questions each jockey must answer.

What are Aidan O’Brien’s chances?

Diamond Necklace brings the strongest headline form. She won the Prix de Diane, but stall 16 asks Christophe Soumillon to find a position without wasting too much ground.

She is not alone. Minnie Hauk finished second in the 2025 Arc and returns with William Buick, giving Ballydoyle a runner who knows the race. Irish Derby winner Benvenuto Cellini has the best draw of O’Brien’s trio. Ryan Moore can save ground from stall one, although the inside can become awkward if the pace and traffic work against him.

Can Joseph O’Brien win with Thundering On?

Thundering On arrives as the sole Joseph O’Brien runner after returning to winning form at the Curragh. She also owns top-level form as an Oaks winner and has drawn stall three.

The concern is the depth of opposition. Defending champion Daryz heads the field, while Maltese Cross and Kalpana are also prominent in the market.

Prix de l’Arc 2026 Irish runner odds

The current market makes Thundering On the shortest-priced Irish-trained runner, with Diamond Necklace next.

Market guide prices checked on 3 October. Confirm the LiveScoreBet Ireland price before betting.

Beto’s take

BetoThe bold one

Beto likes the draw more than the flag. “Benvenuto Cellini in one and Thundering On in three give the jockeys choices, and choices are worth having when 16 horses finally turn for home in Paris.”

What time is the Arc in Ireland and how can you watch?

ITV1 is showing the race as part of its live Arc coverage from 13:00 to 15:30. Irish viewers with access to the channel can follow that broadcast.

For Irish interest, it is a tidy Arc: four runners, two O’Briens and four different tactical problems. Diamond Necklace has the class but the widest stall. Benvenuto Cellini and Thundering On have cleaner starting positions. Minnie Hauk has the experience of finishing second last year.

The best Irish chance may not be the one with the shortest route on the map, or the shortest price. In the Arc, getting the first mile right usually matters far more than winning the first 100 yards.

Odds Opportunities

Thundering On10.00Diamond Necklace15.00Benvenuto Cellini17.00