Arkle (19 April 1957 – 31 May 1970) was an Irish-bred Thoroughbred racehorse. A bay gelding by Archive out of Bright Cherry, Arkle was the grandson of the unbeaten Flat racehorse and prepotent sire Nearco. Arkle was bred by Mary Baker of Malahow House, near Naul, County Dublin, and was born at Ballymacoll Stud, County Meath. He was owned by Anne Grosvenor, Duchess of Westminster, who named him after the mountain Arkle in Sutherland, Scotland, which bordered her Sutherland estate. Trained by Tom Dreaper at Greenogue, Kilsallaghan, in County Dublin, Arkle was ridden during his steeplechasing career by Pat Taaffe.

Arkle won three Cheltenham Gold Cups and a number of other top races before his career was cut short by injury. At 212, his Timeform rating is the highest ever awarded to a steeplechaser.

Arkle, a bay colt with no white markings, was bred by Mary Baker, who kept a few mares on the family farm at Malahow, near Naul in County Dublin. His dam was Bright Cherry, who had won seven times over jumps. His sire was Archive, who, although the offspring of leading sire Nearco, had never won a race and stood at the modest fee of 48 guineas. Arkle was foaled at Ballymacoll Stud in County Meath on 19 April 1957. He was gelded as a yearling.

In August 1960, the yet unnamed gelding was sent to Goff's Bloodstock Sales in Ballsbridge, Dublin, where he was bought for 1,150 guineas by Tom Dreaper on behalf of the Duchess of Westminster. His new owner named him Arkle after a mountain overlooking her Scottish estate. After spending a year at Eaton Hall, the Westminster estate in Cheshire, Arkle returned to Ireland in August 1961 to go into training at Tom Dreaper's yard, Greenogue, at Kilsallaghan, north of Dublin.

Arkle's first racecourse appearance was on 9 December 1961 at Mullingar, where he came third of seventeen in the Lough Ennel Plate, a bumper. It was a race for amateur riders, and he was ridden by the Hon. Mark Hely-Hutchinson, son of Lord Donoughmore (one of Dreaper's major owners). On St Stephen's Day 1961, Arkle ran in another bumper, at Leopardstown. Again ridden by Hely-Hutchinson, he came fourth of ten.

In January 1962, Arkle had his first race over jumps in the Bective Novice Hurdle over three miles at Navan. Stable jockey Pat Taaffe had elected to ride the favourite Kerforo and the ride on Arkle was taken by stable lad Liam McLoughlin. Arkle defeated 26 runners to win by 1+1⁄2 lengths, prompting his trainer to say "I think we've got something there!" In his next race, the Rathconnel Handicap Hurdle over two miles at Naas, he was ridden for the first time by Taaffe. Starting at 2/1 favourite in a field of ten, he won by four lengths.

The season ended with two defeats in April 1962. Arkle, ridden by McLoughlin, finished unplaced in the two-mile Balbriggen Hurdle at Baldoyle, the only time in his career he would finish outside the first four. The pair then finished fourth in the New Handicap Hurdle at Fairyhouse, before Arkle went to spend the summer on his owner's farm at Bryanstown House, Maynooth, County Kildare.

The five-year-old Arkle started the 1962/1963 season with two wins over hurdles in Ireland, ridden on one occasion by Taaffe and on the other, when Taaffe was unable to make the weight, by his regular work rider, Paddy Woods. On 17 November 1962, Arkle ran for the first time over steeplechase fences in the Honeybourne Chase at Cheltenham. Ridden by Taaffe, who would go on to ride him in all his subsequent races over fences, Arkle started at 11/8 favourite and won by 20 lengths. It was his first race in England, and his victory earned him a mention in The Times, where he was described as a "promising type". As a preparation for the 1963 Cheltenham Festival, Arkle was entered in the Milltown Novice Chase at Leopardstown in February. He went off as 1/2 favourite and won by eight lengths. The race was later renamed the Arkle Novice Chase in his honour.