The Spanish giants provide more representatives in the 23 than Portuguese champions Benfica, who have just two players included despite claiming an unprecedented treble and reaching the Europa League final this season.
Only eight of the squad overall play their club football in Portugal, with players from Turkey, Russia, Ukraine, France, Germany and Italy included.
The Premier League's sole representative in the squad is Manchester United winger Nani.
Portugal, who have been drawn in Group G alongside Germany, the United States and Ghana, will get their campaign underway against the Germans on June 16.
Find out who Sports Mole named the country's greatest ever player here.
Portugal World Cup squad:
Goalkeepers: Beto (Seville), Eduardo (Braga) and Rui Patricio (Sporting Lisbon)
Defenders: Andre Almeida (Benfica), Bruno Alves (Fenerbahce), Fabio Coentrao (Real Madrid), Joao Pereira (Valencia), Neto (Zenit St Petersburg), Pepe (Real Madrid), Ricardo Costa (Valencia)
Midfielders: Joao Moutinho (Monaco), Miguel Veloso (Dinamo Kiev), Raul Meireles (Fenerbahce), Ruben Amorim (Benfica), William Carvalho (Sporting Lisbon), Rafa (Braga)
Forwards: Cristiano Ronaldo (Real Madrid), Eder (Braga), Helder Postiga (Lazio), Hugo Almeida (Besiktas), Nani (Manchester United), Varela (FC Porto), Vieirinha (Wolfsburg)