Gonzalo Fernández-Castaño (born 13 October 1980) is a Spanish professional golfer.
Fernández-Castaño was born in Madrid. He turned professional in 2004 and came eighth at that year's European Tour Qualifying School.
In his 2005 rookie season on the Tour, he won the KLM Open and the Sir Henry Cotton Rookie of the Year award. In 2006 he won the BMW Asian Open, which was co-sanctioned by the European Tour and the Asian Tour.