Reyes was a long-time member of the senior Spain men's national basketball team. With Spain's senior national team, he won the following medals: the bronze medal at the 2001 EuroBasket, the silver medal at the 2003 EuroBasket, the gold medal at the 2006 FIBA World Cup, the silver medal at the 2007 EuroBasket, the silver medal at the 2008 Summer Olympics, the gold medal at the 2009 EuroBasket, the gold medal at the 2011 EuroBasket, the silver medal at the 2012 Summer Olympics, the gold medal at the 2015 EuroBasket, and the bronze medal at the 2016 Summer Olympics. With Spain, he also played at the 2002 FIBA World Cup, the 2004 Summer Olympics, the 2005 EuroBasket, the 2010 FIBA World Cup, and the 2014 FIBA World Cup.