Marcos Antonio Serrano Rodríguez (born 8 September 1972 in Redondela, Province of Pontevedra) is a professional cyclist from Galicia, Spain. Turning professional in 1993, he joined the Kelme team and then in 1999 the lottery-sponsored Organización Nacional de Ciegos Españoles (ONCE). He remained part of the same team when in 2004 sponsorship and name passed to Liberty Seguros-Würth and in 2006, as the Astana-Würth Team.
His most significant achievement was victory in the Milano–Torino in 2004. Other palmarès include victory in the 18th stage of the 2005 Tour de France and in the 5th stage of the 1999 Tour of Galicia. His best overall classification in the Tour de France was a ninth place finish in 2001.