Son of the American star Greg Duplantis and a US citizen, from 2015 he opted for his mother's Swedish sports nationality while retaining his dual nationality. At the age of eighteen at the 2018 European Athletics Championships in Berlin he won the gold medal in pole vaulting, measuring 6.05 meters.
On this occasion he set the new under 20 world record, overcoming the twenty-one year old Russian Timur Morgunov (6.00 meters) and the French Renaud Lavillenie, world record holder. In 2019 he won the silver medal at the Doha World Championships with 5.97 m, preceded by the same measure by the American Sam Kendricks.
On 8 February 2020, in Toruń, she set the new world record, with the measurement of 6.17 meters, thus exceeding by one centimeter the previous record of Lavillenie which had lasted since 2014. Exactly one week later, on 15 February, in Glasgow, has set the world record again, raising it by one centimeter and thus bringing it to 6.18 meters.
Both performances, despite having been established indoors, are ratified as a world record under rule 260 of the international federation introduced in 1998, which provides that world records can be established in facilities with or without coverage.
Duplantis' record at the Belgrade 2022 Indoor World Championships
On 17 September, on the occasion of the Golden Gala Pietro Mennea in Rome, he realizes the best outdoor performance ever with the measure of 6.15 m. In 2020 he was named World Athlete of the Year by World Athletics.
He represented Sweden at the Tokyo 2020 Summer Olympic Games, where he won the gold medal in pole vaulting, thanks to the 6.02 meter measurement, overtaking the American Chris Nilsen and the Brazilian Thiago Braz da Silva in the final.
After numerous attempts in the previous months, on 7 March 2022 at the Štark Arena in Belgrade he improves his world record to 6.19 meters. Armand Duplantis rewrites the history of pole vaulting, retouching his World Record once again, at the Indoor World Championships in Belgrade, where the Swede exceeded 6.20 meters, improving by one centimeter what he did on March 7th in this very spot plant.
The Tokyo 2020 Olympic Champion celebrated with a roar addressed to the crowd in the stands of the Stark Arena in Belgrade and kissing his girlfriend. Armand Duplantis made a clear course (5.60, 5.85, 5.95, 6.05), bringing all opponents to their knees.
The last to surrender was the Brazilian Thiago Braz, Olympic Champion in Rio 2016: the South American overcame 5.95 in the third round, but the next quota proved to be impassable. Third place for the American Christopher Nielsen.