Daley Thompson was born in Notting Hill, London, the second son of a British Nigerian father, Frank Thompson, who ran a minicab firm, and Scottish mother, Lydia, from Dundee.

Initially, Thompson was a member of Haywards Heath Harriers, but when he returned to London in 1975 he joined the Newham and Essex Beagles Athletics club, training as a sprinter. He began to be coached by Bob Mortimer, who suggested he try for decathlon. He competed in his first decathlon later that year in Cwmbran, Wales, which he won along with his next competition. In 1976, he won the AAA title and was 18th at the Montréal Olympic Games. The following year, he won the European Junior title and in 1978 came the first of his three Commonwealth titles. In 1979, he failed to finish in his only decathlon of that year, but won the long jump at the UK Championships.

Thompson opened the 1980 Olympic season with a world decathlon record of 8,648 points at Götzis, Austria, in May, and followed this by winning gold at the Moscow Olympics. After a quiet 1981 season, he was in top form in 1982; back at Götzis in May, he raised the world record to 8,730 points and then in September, at the European Championships in Athens, he took the record up to 8,774 points. The following month in Brisbane, Thompson took his second Commonwealth title.

In 1983, Thompson won the inaugural World Championships and became the first decathlete to hold a continental title, in his case the European title, and the World and Olympic titles simultaneously. He also became by virtue of his World title, the first athlete in any athletics event to hold Olympic, World, continental and Commonwealth Games titles in a single event simultaneously.

Thompson spent much of the summer of 1984 in California preparing for the defence of his Olympic title, with Jürgen Hingsen, the West German who had succeeded Thompson as the world record holder, expected to be a major threat. Thompson took the lead in the first event, a lead he never relinquished throughout the competition. It seemed that, by easing off in the 1,500 metres, he had missed tying the world record by just one point. When the photo-finish pictures were examined, however, it was found that Thompson should have been credited with one more point in the 110 metres hurdles so he had in fact, equalled Hingsen’s record.

When the new scoring tables were introduced, Thompson became the sole record holder once more with a recalculated score of 8,847 points – a world record that stood until 1992.

Thompson’s two victories in the Olympic decathlon are a feat shared only with the Americans Bob Mathias and Ashton Eaton. Thompson’s 1984 performance is still the UK record. In 2002, Thompson’s successful defence of his Olympic title was ranked number 34 on Channel 4’s poll of the 100 Greatest Sporting Moments.