Francisco Mancebo Pérez (born 9 March 1976 in Madrid) is a Spanish professional cyclist. He initially rode for team Illes Balears–Banesto, but moved to AG2R Prévoyance in 2006.

Mancebo is a stage race specialist, with good climbing and individual time trial performances. He was the Spanish National Champion in 2004. He finished sixth in the 2004 Tour de France and fourth in the 2005 Tour de France. He also won a stage of the 2005 Vuelta a España and finished third in the general classification, making the podium for the second consecutive year.

At the 2000 Tour de France, he won the maillot blanc for the best young rider.

Mancebo was himself implicated in Operación Puerto and was pulled from that year’s Tour de France on the eve of the race. Contrary to reports circulating at the time, Mancebo denies that he ever retired after news of the affair broke. “I never retired. Some journalists said I did, but that never happened,” Mancebo told Cyclingnews. “I changed my focus.”

In the 2009 season, he rode with the team Rock Racing. For 2010 he rode with Heraklion Kastro-Murcia and with the Canyon Bicycle's Team in the Tour of Utah, in an effort to defend his overall classification title. In 2011, he rode with the Realcyclist.com Cycling Team, where he was the #1 rider in the NRC standings. For 2012 he rode with the Competitive Cyclist Racing Team repeating as the NRC Champion and named Stage Racer of the Year by VeloNews. 2013 saw Mancebo ride under the colors of 5-hour Energy.

Mancebo joined the Continental squad Skydive Dubai Pro Cycling for its debut season in 2014. He stayed with the team through to the 2016 season: in April 2017 Canyon Bicycles announced that they had signed him for 2017.