Ferenc Szonyi (born Komárom, 25 August 1964) is a Hungarian ultra-triathlete and ultra-runner.
At the age of 40, he took up the triathlon and soon realized that he could excel as runner and triathlete in longer distances.
He finished at 4th place in his first double Ironman race, in Bonyhád, Hungary, in 2008, after which he participated in several extreme distance events, like the Vienna–Bratislava–Budapest Supermarathon in his home country and in the Deca-Ironman, which consists of 38 kilometers of swimming, 1800 kilometers of cycling and 422 kilometers of running, and even the Double Deca-Ironman, both held in Monterrey, Mexico.
In 2018, he won the Decaman ultratriathlon in New Orleans and by the president of Hungary he was bestowed Knight of the Order of Merit of the Hungarian Republic (Civilian).