Joseph Scott was born, probably on 3 June 1860, at Lettermacaward, in County Donegal, Ireland, the son of John Scott and his wife, Hannah McElheny. John Scott was a member of the Irish Constabulary. He and his family emigrated to Victoria, Australia, about 1861, and he was one of the policemen brought from there to Otago by St John Branigan in 1861 or 1862. He settled in Dunedin and was later described as a labourer.
Joe entered the bootmaking trade in Dunedin at the age of 13. Racing in the street with other boys at lunch-breaks, he attracted the attention of Alfred Austin, handicapper to various athletic sports, who trained him as a competitive walker. Walking, or pedestrianism, was then a very popular sport, in which human endurance was pushed to its limits. The races were held in hot, crowded, smoky halls; the competitors became very thirsty and in longer events lack of food caused digestive problems: Scott regularly suffered from nausea, vomiting and diarrhoea during races.
Scott's first public appearance was in a two-mile walk at the Caledonian sports of 1874. Although he was disqualified for breaking into a run, the performance of the 'plucky little fellow' – apparently just three feet six inches tall and out-walking tall men – was astonishing. He was presented to the governor, Sir James Fergusson, who is reputed to have said, 'Bravo, little man.…Some day you'll be champion of the world!'
Joseph Scott had his first chance at an international contest in 1875. The Australian champion William Edwards visited Dunedin and displayed his skill by walking 100 miles in 24 hours. Austin then announced that 'The boy Scott' would walk 100 miles around Queen's Theatre – which he did, in 23 hours 53 minutes. When Edwards challenged him to a seven-mile race, Scott defeated the visitor, in 60 minutes 26 seconds.
Over the next decade, despite occasional losses, Scott achieved many remarkable feats. In 1879 he was named champion of New Zealand after walking 106 miles in 24 hours against eight other leading walkers. He defeated Edwards again in 1883, in both 24-hour and 48-hour contests. In 1885 he defeated the visiting British champion, Arthur Hancock, by walking 114 miles in a 24-hour match, as well as in other contests. Huge crowds paid to watch these events at the Garrison Hall.
In 1885, walking alone, Scott walked 100 miles in 17 hours, 59 minutes, beating the world record by eight minutes. In 1886 he spent some months in Australia, and was declared champion of that country after walking 424 miles in a six-day contest against Edwards. He also triumphed over a well-known visiting American pedestrian, C. A. Harriman, by walking 271 miles in 75 hours.
In October 1887 Scott visited England, where in February 1888 he defeated Arthur Hancock in 12-hour and 24-hour contests. Hancock, it was said, 'stood just about as much chance as a carthorse would against a thoroughbred.' However, Scott's greatest achievement was in a 72-hour match at the Agricultural Hall, London, in May, in which he covered 363 miles 1,510 yards – 'the best performance on record'. (The previous record had been set in the United States in 1880.) This performance won him the world championship belt. He then toured England, racing and giving walking displays. He arrived home to be given a hero's welcome at the Caledonian sports of 1889. Wearing his heavy silver championship belt, he was paraded around the ring as the band played 'See the conquering hero comes!'
Scott's achievements brought him no financial rewards. He had won many big prizes – £100 in 1885, 100 sovereigns in 1886 – but a considerable proportion of his winnings may have gone to his manager and backers. He had married Isabella Rachel Jarvis at Dunedin on 8 December 1881, and he said his family survived while he was in England only by selling his cups and medals. In spite of pawning his championship belt, he still had heavy debts and in March 1889 was declared bankrupt. Supporters attempted to raise money to set Scott up in business. He worked as a bootmaker, and also continued occasionally to walk competitively and win prize money, but was never financially secure. He died at Dunedin of cancer, on 9 February 1908, leaving his wife, five daughters and two sons in poor circumstances. Fellow-sportsmen collected £45 4s. 11d. to raise a memorial headstone.