No one on a national or international level has won all ten events in one given decathlon.
The origin of the word decathalon is a combined event in athletics consisting of ten track and field events and is greek in origin and is won by the contestant that has the highest total score.
The easy answer is one, as in the Decathlon is a single event worth a single gold medal. The more complex answer is also one. The Decathlon is comprised of ten events with all decathletes competing in all of them for points. Out of the decathletes in the 1976 competition Jenner only won one event, the Discus. He was 8th in the 100 and Long Jump, 7th in the 110 hurdles, 4th in the Javelin and 2nd in the Shot Put, High Jump, 400, Pole Vault and 1500
Bruce Jenner won a gold medal in the men's decathlon at the 1976 Summer Olympics in Montreal, Canada. The decathlon is a combined event in athletics consisting of ten track and field events. Jenner's victory in the decathlon made him a celebrated athlete and a prominent figure in sports history.
Leonel Suarez Cuba (CUB)
Ashton Eaton United States (USA)
Trey Hardee United States (USA)
Kevin Mayer won the silver medal in the Men's Decathlon event at the Rio 2016 Olympics.
The bronze medal in the Men's Decathlon event at the Rio 2016 Olympics was won by Canada.
The gold medalist in decathlon at the 2008 Games in Beijing was Bryan Clay of the United States. Andrei Krauchanka of Belarus won silver and Leonel Suarez of Cuba won bronze.
Bruce Jenner was a decathlete and won the gold medal in decathlon at the 1976 Summer Olympics in Montreal.
Damian Warner is the athlete who won the bronze medal in the Men's Decathlon event at the Rio 2016 Olympics.
Women do not compete for a gold medal in the decathlon yet. The women do a 7 event Heptathlon, which was won in 2012 by Jessica Ennis.