Contador, considered one of the top grand tour cyclists in the world, told the Associated Press that "next year will most likely be my last."
The Spaniard, who will begin his season at the Tour of Andalusia this week, is confident that 2016 will be his final year in the sport.
"I could change my mind if I have a mishap on the Tour like last year," Contador said, "...but little else could make me change.”
Contador failed to finish last year's Tour de France after crashing on the race's 10th stage. Later in the year, he won the Tour of Spain for the third time.
Contador, 32, won the Tour de France in 2007 and 2009. He initially was declared the winner of the 2010 race, but was stripped of the result after a 2012 ruling by the Court of Arbitration for Sports found him guilty of accidental ingestion of a banned doping product. He also served a one-year suspension and had his 2011 Giro d'Italia win taken away.