Demong competed at the World Cup level starting in 1997. His first World Cup victory came in 2002 in (
Liberec, Czech Republic). Two more in 2007, (
Lahti, Finland: March 9;
Trondheim, Norway: December 8). He also has three victories in World Cup B events in the United States in 2004 and 2005 as well. In the 2008 season Bill had one victory in Ramsau am Dachstein in the 2008 season but his first real banner year occurred in 2009 when Bill racked up five World Cup victories and took third in the overall World Cup standings. Heading into the 2009–2010 season, Demong had nine World Cup victories and numerous top-tens. At the
2002 Winter Olympics, in
Salt Lake City, Demong placed fourth in the 4 × 5 km team event and 14th in the 7.5 km event. Demong won a complete set of medals at the
FIS Nordic World Ski Championships with a gold (10 km individual large hill:
2009), a silver (15 km individual:
2007), and a bronze (10 km individual normal hill: 2009). Demong retired in 2015.
2010 Winter Olympics event at the
2010 Winter Olympics Demong skied the final lap for the United States team consisting of
Johnny Spillane,
Todd Lodwick and
Brett Camerota in the team large hill/4x5 km, winning the silver medal. In the
10 km individual large hill, Demong won gold. Demong is the first American to win an Olympic gold medal in a nordic event. After the medal ceremony held later that evening for the 10 km individual large hill event, Demong proposed to his girlfriend,
Katie Koczynski, in front of teammates and coaches at the team headquarters near
Vancouver. Koczynski said yes. On July 11, 2010, Demong married Koczynski in
Lake Placid, New York. ==Personal life==