Fabian Cancellara (born 18 March 1981), nicknamed "Spartacus", is a Swiss cycling executive, businessman and former professional road racing cyclist who last rode for UCI ProTeam Lidl–Trek. He is known for being a quality time trialist, a one-day classics specialist, and a workhorse for his teammates who have general classification aspirations.

He won two consecutive World Junior Time Trial Championships in 1998 and 1999. At age nineteen he turned professional and signed with the Mapei–Quick-Step team, where he rode as a stagiaire. After winning a few stages and small races in his starting years, Cancellara earned his first major victory at the 2004 Tour de France, where he won the opening prologue time trial and wore the race leader yellow jersey for one day. The following season saw fewer victories, but his 2006 season saw a victory in the men's time trial at the UCI Road World Championships, along with victory at the Paris–Roubaix. Cancellara repeated as world champion in the time trial the next year, along with winning two stages at the Tour de France.

During the 2008 calendar he won gold at the Summer Olympics in the individual time trial event and the Milan–San Remo. The next season saw Cancellara again become world time trial champion and lead both the Tour de France and the Vuelta a España. In 2010, he won the Paris–Roubaix and the Tour of Flanders. Cancellara's 2011 and 2012 campaigns were both short in number of victories, while the latter was hampered by injuries throughout. After a lackluster two-year period, Cancellara again won the Tour of Flanders and Paris–Roubaix double in 2013. In 2014, Cancellara repeated as winner of the Tour of Flanders.

Since turning professional in 2000, Cancellara has ridden for four professional teams. He has achieved great success in the classic monuments; he has won Paris–Roubaix three times, the Milan–San Remo once, and the Tour of Flanders three times. Cancellara has won the opening stage of the Tour de France five times and has led the race for 29 days total, which is the most of any rider who has not won the Tour. His success has not been limited to just time trials and classics, as he has won general classification of the Tirreno–Adriatico, Tour de Suisse, and the Tour of Oman. In 2008, he won gold in the individual time trial and silver in the men's road race at the Summer Olympics. In 2016, he won Olympic gold in the individual time trial for the second time in his career. In addition, Cancellara has been the time trial world champion four times in his career.