Octagonal (8 October 1992 – 15 October 2016) was a champion New Zealand-bred, Australian racedThoroughbred racehorse, also known as 'The Big O' or 'Occy'. He was by the championsireZabeel, out of the champion broodmareEight Carat, who also producedGroup One winners Mouawad, Kaapstad, Diamond Lover and (Our) Marquise.

Bob Ingham, along with brother Jack Ingham, purchased and raced Octagonal. Trained byJohn Hawkes, Octagonal made his debut late in 1994, and was crowned theAustralian Champion Two Year Old on the strength of his autumn campaign, which comprised wins in the Todman Trial andAJC Sires Produce Stakes and close seconds in the STCGolden Slipper and AJCChampagne Stakes.

As a three-year-old, Octagonal won seven of his eleven starts, and took his record to 10 wins from 16 starts. In addition to beating a high-standard crop in Sydney's three-year-old autumn triple crown - theCanterbury andRosehill Guineas and theAustralian Derby - Octagonal won the two richest weight-for-age races on the Australian calendar, theW. S. Cox Plate and theMercedes Classic. With earnings of just short of A$4 million, Octagonal was voted the 1996Australian Champion Three Year Old,Australian Horse of the Year, and remains the last horse to have won the triple crown. The Victoria (spring) and Australian Derby (autumn) double eluded him, however, as he was narrowly defeated by Nothin' Leica Dane in theVictoria Derby.

Octagonal returned to the track as a four-year-old, but his win theUnderwood Stakes was the only highlight of a spring campaign that saw him unplaced in six of his seven starts. Meanwhile, the horses who had finished second to him in the triple crown -Saintly and Filante - won three races each, including the Epsom Handicap, theW. S. Cox Plate (where they were first and second), and theMelbourne Cup. Octagonal's final campaign, during the autumn, was more consistent, and featured Group One wins in consecutive starts in theChipping Norton Stakes,Australian Cup, and theMercedes Classic. At his final start, he was runner-up in the AJC Queen Elizabeth Stakes; a feat coincidentally emulated in the farewell of his champion son, Lonhro, seven years later.

Octagonal retired to stud after 28 starts with a record of 14 wins (10 Group 1), 7 seconds (6 in GI or GII races) and a third. He ended his racing career with a stakes tally of A$5,892,231, the highest of any galloper in Australasia to that point.

Octagonal Entered stud in 1997–2013 Woodlands Stud atCootamundra, New South Wales and Shuttled in 1998–2001 to Haras du QuesnayFrance and was pensioned from stud duties in 2013.^[1] He is the sire of Australian Group One winning brothersLonhro and Niello, the South African Group 1 winner, Suntagonal and Laverock whose wins include two Group 1 races: thePrix d'Ispahan atLongchamp Racecourse inParis and theGran Premio del Jockey Club atMilan,Italy's,San Siro Racecourse.

He was euthanized on 15 October 2016 at the age of 24 years at Woodlands Stud at Denman in the NSW Hunter Valley. He was buried next to his fellow stallion mate Canny Lad. Owner Bob Ingham described his career as 'heroic' and 'life-changing'.^[2]

Octagonal's major race winners include:

• Australian Champion Racehorse of the Year
• List of millionaire racehorses in Australia

• Octagonal at Stallions.com.au
• Octagonal's pedigree and partial racing stats

• 1992 racehorse births
• 2016 racehorse deaths
• Australian Champion Racehorse of the Year
• Racehorses bred in New Zealand
• Racehorses trained in Australia
• Cox Plate winners
• Triple Crown of Thoroughbred Racing winners
• Australian Racing Hall of Fame horses
• Thoroughbred family 9-c

• Articles with short description
• Short description matches Wikidata
• Use dmy dates from November 2023
• Use Australian English from November 2011
• All Wikipedia articles written in Australian English