Iban Mayo Diez (born 19 August 1977 in Igorre, Basque Country, Spain) is a former professional road bicycle racer.

Renowned as a climber, Mayo turned pro with Euskaltel–Euskadi in 2000, and became one of the Basque Country's prospects for glory. He stayed with Euskaltel-Euskadi throughout 2000–2006. The biggest result came in the 2003 Tour de France, when he won a stage up Alpe d'Huez. Mayo finished the Tour sixth.

In 2004 Mayo won the Critérium du Dauphiné Libéré, regarded as preparation for the Tour de France. He beat Lance Armstrong by two minutes in a time trial on Mont Ventoux, breaking the record.^[1] He was seen as a dangerous outsider for the Tour de France in the same year. It turned out a disappointment,^{[clarification needed]} and after losing time due to a crash, he lost more in the Pyrenees due to injuries and mononucleosis. Mayo quit before the 15th stage.

After a lackluster^{[clarification needed]} 2005, in 2006 he returned in the Dauphiné Libéré with second place in Briançon and a win on the stage to La Toussuire. He was seen^{[by whom?]} as a contender for the 2006 Tour de France, but retired during the 11th stage. In 2007 Mayo signed for Saunier Duval–Prodir.

Mayo won the 19th stage of the 2007 Giro d'Italia. On 30 July 2007 the UCI confirmed he had failed a test for EPO during the Tour de France, in which he finished 16th.^[2] On 22 October the Spanish federation cleared Mayo after a second test proved negative.^[3] The UCI president Pat McQuaid stopped short of clearing the rider, pending further tests.^[4]

On 19 December a French laboratory confirmed the positive test.^[5] In 2008, the Court of Arbitration for Sport upheld Mayo's two-year ban, which ended on 31 July 2009.^[6]

On 13 September 2009, Mayo decided not to make a comeback to professional cycling, thus effectively ending his career.^[7]

• List of doping cases in cycling