Along with the Mineirao in Belo Horizonte, to be opened on December 21, they are the only stadiums to meet the December 2012 deadline set originally for next year's Confederations Cup, a World Cup finals dress rehearsal.
President Dilma Rousseff attended the opening ceremony at the Castelao, which has been completely refurbished at a cost of 518.6 million Brazilian reals (£153.5 million) with a capacity for 67,000.
She said inauguration of the first stadium for the 2014 tournament and Corinthians' victory in the Club World Cup final in Japan earlier on Sunday showed Brazil's strength on and off the soccer field.
"Brazil is capable of both things, winning on the football fields and building a stadium of this standing," she said.
The biggest of the north-eastern venues, Castelao will host six World Cup matches including one of Brazil's in the first round, a second-round game and a quarter-final.
It will also host three Confederations Cup matches including Brazil's group stage meeting with Mexico on June19, the stadium's debut in an official FIFA tournament.
FIFA extended the deadline for the other Confederations Cup venues, Brasilia, Recife, Rio de Janeiro and Salvador, until March while the remaining World Cup stadiums will be completed sometime during 2013.
"This is a very special day for us at FIFA because it marks the two great events that will take place in Brazil in the coming years, the Confederations Cup and the World Cup," FIFA president Sepp Blatter said in Tokyo where he was attending the Club World Cup and shown at the Castelao.
Brazil's World Cup preparations have been criticised several times by FIFA due to delays notably with airports and urban transport with the world body's general secretary Jerome Valcke once memorably saying the country needed "a kick in the backside".