Jason Lamy Chappuis was born in the United States of America. His mother is American. Today the family lives in Bois-d'Amont , his father's native village in the French Jura . He made his debut in February 2004 at the World Cup in Oslo . His first outstanding result in the World Cup was a fourth place in the Gundersen competition in September 2005 in Kuusamo . In March 2006, he won his first World Cup sprint in Sapporo . At the 2006 Olympic Games in Turin , Lamy Chappuis competed in all three Nordic combined competitions. In the Gundersen competition he was eleventh, with the team fifth and in the sprint he just missed a medal in fourth behind the German Georg Hettich . Before that, he competed in the Nordic World Ski Championships in Oberstdorf in 2005 , but was unable to achieve any notable success.
In the 2006/07 season Lamy Chappuis won the overall ranking in the Sprint World Cup, and in the overall World Cup he finished second. In the mass start competition held for the first time in the Nordic World Ski Championships in Liberec , he won the bronze medal on February 20, 2009 and eight days later also bronze in the Gundersen competition on the large hill. The 2009/10 season was a successful one for Lamy Chappuis. It began with a win at the start of the season in Kuusamo, further victories followed in Lillehammer and twice in Ramsau am Dachstein . At the end of the season he won the overall World Cup by superiority.
On February 22, 2013, at the 2013 World Championships in Val di Fiemme , Italy , he won the gold medal in the Gundersen individual competition on the normal hill. After the jumping, Lamy Chappuis was still in 11th place 1 minute 13 seconds behind the leading Håvard Klemetsen , in the subsequent ten-kilometer run he made up space by space and reached the finish line first. Two days later he won another gold medal from the same hill, for the first time with his colleagues Sébastien Lacroix , François Braud and Maxime Laheurte in the team competition. In the individual race on the large hill, he won the bronze medal. In the final team competition he was able to look forward to a world championship title again, which he won with his teammate Sébastien Lacroix.
At the 2015 World Championships in Falun , he won the bronze medal in the first individual competition on the normal hill, and in the second individual competition on the large hill, he took 6th place. In the team competition, in which France started as the defending champion, he won the bronze medal together with Maxime Laheurte , Sébastien Lacroix and François Braud . After winning the team sprint with François Braud, he announced his retirement from competitive sport at the end of the 2014/15 season. In the 2017/18 season he returned to the World Cup for a year.
Ski jumping
So far Jason Lamy Chappuis has been in the French team three times in World Cup team competitions. The best result was reaching the finals and 8th place in the ski flying in Planica in March 2011. At the French championships in 2011 in Chaux-Neuve , he won the individual title among the special jumpers. His last participation in the special jumpers competition took place in 2013.