At the 2000 Olympic Games in Sydney, Sebrle came agonizingly close to winning the gold medal. In the end, he finished only 35 points behind Erki Nool of Estonia. Performing in Götzis, Austria, 26-27 May 2001, Sebrle became the first person in history to break the 9000-point barrier when he scored 9026 points. He also set the decathlon world record for the long jump with a leap of 8.11 metres.
In 2004, Sebrle started slowly at the Olympic Games in Athens, but set a personal best in the shot put to put himself into second place after the first day of competition. With seven events gone, he trailed Dmitri Karpov of Kazakhstan by 166 points. But by clearing 5 metres in the pole vault, he closed the gap to 46 points. Sebrle then moved ahead with a javelin throw of 70.52 metres and held off Bryan Clay of the United States in the 1,500m to win the competition by 73 points. He also broke the 20-year-old Olympic record. When asked how he intended to celebrate his Olympic championship, Sebrle replied, "I'm going to eat everything that is bad for an athlete."