Willi Denifl started skiing at the age of nine and made his debut at the World Cup in Breitenwang, Austria, in 2000. A highlight of his career came in 2003 when he won the Gold medal in the team event at the World Championships in Val di Fiemme. But the resident of Fulpmes, Austria also got to know the darker side of the life as an athlete when he sustained injuries right at the beginning of three different seasons, which ended all aspirations towards the respective overall World Cups. In 2004, he had an especially bad injury when his binding did not open during a jump in Seefeld and he incured an open fracture on his leg.

Nevertheless, Willi loves all kinds of sports for example cycling, motor cycling, diving, tennis and golf. On top of that, he likes to spend time with his wife Ute and daughter Nina.

He returned to the sunny side of his profession in the seasons of  2012/13 and especially 2013/14 when he not only managed to extend his merit list with four podium results but also with his first World Cup victory (at the ripe age of 34) at Chaikovskiy, Russia. In 2015/16 he followed up with a third rank in Kuopio, Finland. The 2016/17 season also brought success to the veteran: two second places in Ruka and Schonach brought his podium total to eight and he just narrowly missed a bronze medal in the Team Sprint at the World Championships in Lahti together with Bernhard Gruber. Denifl finished ninth in the overall standings that winter.