| Class: | Listed |
| Horse Race: | Diamond Stakes |
| Location: | Dundalk Stadium County Louth, Ireland |
| Race Type: | Flat / Thoroughbred |
| Sponsor: | Al Basti |
| Website: | Dundalk |
| Distance: | 1m 2f 150y (2,149 m) |
| Surface: | Polytrack |
| Track: | Left-handed |
| Qualification: | Three-years-old and up |
| Weight: | 9 st 3 lb (3yo); 9 st 8 lb (4yo+) Allowances 3 lb for fillies and mares Penalties 5 lb for Group 1 winners * 3 lb for Group 2 winners * * since 1 January |
| Purse: | €50,000 (2021) 1st: €29,500 |
|}The Diamond Stakes is a Listed flat horse race in Ireland open to thoroughbreds aged three years or older. It is run at Dundalk over a distance of 1 mile, 2 furlongs and 150 yards (2,149 metres), and it is scheduled to take place each year in September or October.
The event was formerly classed at Listed level and contested on turf over 1 mile and 2 furlongs. For a period it was held at Phoenix Park, and it switched to the Curragh in 1991. It used to be restricted to fillies and mares, but it was opened to male horses in 2001. It was staged at Fairyhouse in 2006 and 2007.
The Diamond Stakes moved to Dundalk in 2008, and since then it has been run on a Polytrack surface over 1 mile, 2 furlongs and 150 yards. It became Ireland's first non-turf Group race in 2009, when it was promoted to Group 3 status.[1] It was downgraded back to Listed status in 2022.[2]
The Diamond Stakes was added to the Breeders' Cup Challenge series in 2009, with the winner earning an automatic invitation to compete in the Breeders' Cup Marathon. It was removed from the series in 2011.
Most successful horse since 1988: (2 wins)
Leading jockey since 1988 (5 wins):
Leading trainer since 1988 (8 wins):
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| Year | Winner | Age | Jockey | Trainer | Time | |||
|---|---|---|---|---|---|---|---|---|
| Turf before 2008 | ||||||||
| 1988 | width=150px | Karaferya | 3 | width=160px | John Reid | width=170px | Michael Stoute | 2:02.40 |
| 1989 | Bex | 3 | Willie Carson | Robert Armstrong | 2:04.60 | |||
| 1990 | Santella Bell | 3 | Warren O'Connor | Michael O'Brien | 2:07.20 | |||
| 1991 | Elfaslah | 3 | Richard Hills | Harry Thomson Jones | 2:16.10 | |||
| 1992 | Misako-Togo | 3 | Michael Kinane | Dermot Weld | 2:11.10 | |||
| 1993 | Eurostorm | 3 | Pat Gilson | Con Collins | 2:18.30 | |||
| 1994 | Ballykett Nancy | 3 | Kevin Manning | Jim Bolger | 2:20.40 | |||
| 1995 | Viaticum | 3 | Joanna Morgan | Noel Meade | 2:09.60 | |||
| 1996 | French Ballerina | 3 | Michael Kinane | Pat Flynn | 2:14.20 | |||
| 1997 | Red Affair | 3 | Pat Shanahan | John Oxx | 2:07.80 | |||
| 1998 | Darina | 3 | Kevin Manning | Jim Bolger | 2:18.40 | |||
| 1999 | Remuria | 3 | Niall McCullagh | John Oxx | 2:23.90 | |||
| 2000 | Dolydille | 4 | Kevin Manning | Jim Bolger | 2:18.10 | |||
| 2001 | Jammaal | 4 | Pat Smullen | Dermot Weld | 2:13.90 | |||
| 2002 | Miss Honorine | 3 | Johnny Murtagh | John Oxx | 2:08.10 | |||
| 2003 | Napper Tandy | 3 | Kevin Manning | Jim Bolger | 2:04.00 | |||
| 2004 | Mikado | 3 | Colm O'Donoghue | Aidan O'Brien | 2:11.40 | |||
| 2005 | The Carbon Unit | 3 | Wayne Lordan | Con Collins | 2:13.90 | |||
| 2006 | Mountain | 3 | Kieren Fallon | Aidan O'Brien | 2:15.00 | |||
| 2007 | Arch Rebel | 6 | Fran Berry | Noel Meade | 2:04.86 | |||
| Polytrack after 2007 | ||||||||
| 2008 | Muhannak | 4 | Pat Smullen | Ralph Beckett | 2:11.63 | |||
| 2009 | Mastercraftsman | 3 | Johnny Murtagh | Aidan O'Brien | 2:12.18 | |||
| 2010 | Gitano Hernando | 4 | Kieren Fallon | Marco Botti | 2:12.94 | |||
| 2011 | Freedom | 3 | Seamie Heffernan | Aidan O'Brien | 2:10.92 | |||
| 2012 | Declaration of War | 3 | Joseph O'Brien | Aidan O'Brien | 2:11.66 | |||
| 2013 | Parish Hall | 4 | Kevin Manning | Jim Bolger | 2:10.97 | |||
| 2014 | Cat O'Mountain | 4 | Fran Berry | Charlie Appleby | 2:09.76 | |||
| 2015 | Panama Hat | 4 | Chris Hayes | Andy Oliver | 2:17.39 | |||
| 2016 | Long Island Sound | 3 | Seamie Heffernan | Aidan O'Brien | 2:14.50 | |||
| 2017 | War Decree | 3 | Donnacha O'Brien | Aidan O'Brien | 2:12.66 | |||
| 2018 | Mootasadir | 3 | Pat Cosgrave | Hugo Palmer | 2:12.52 | |||
| 2019 | Blenheim Palace | 3 | Donnacha O'Brien | Aidan O'Brien | 2:12.97 | |||
| 2020 | Bowerman | 6 | Colin Keane | Adrian McGuinness | 2:13.56 | |||
| 2021 | Bear Story | 3 | Ronan Whelan | Michael Halford | 2:13.60 | |||
| 2022 | Bear Story | 4 | Ronan Whelan | Michael Halford | 2:15.26 | |||
| 2023 | Piz Badile | 4 | Gavin Ryan | Donnacha O'Brien | 2:13.44 |