Diego Zarzosa Peña (born 25 December 1975 in Valladolid) is a Spanish rugby union hooker who plays for CR El Salvador in the División de Honor.
Zarzosa represented Spain during the 1999 Rugby World Cup. In 2007, Zarzosa signed a six-months contract with English giants Harlequins after Samoan Tani Fuga was called to the World Cup squad and Chris Brooker suffered a shoulder injury. He was not able to debut in the Premiership. Later that year, he became the second Spanish-born rugby player to play for the Barbarians.
Zarzosa holds currently 45 caps for Spain, with 3 tries scored, 15 points in aggregate.