The goalkeeper's girlfriend, sports journalist Sara Carbonero, gave birth to a baby boy, Martin, in the Spanish capital
The 32-year-old goalkeeper's girlfriend, Sara Carbonero, gave birth to a baby boy, Martin, at the Ruber International Clinic in the Spanish capital on Friday.
The sports journalist was forced to undergo a caesarean section but Casillas was delighted to confirm later in the day that both mother and child were doing well.
"I want to share with you all the most important moment of my life: the birth of my son," he wrote on his own official website.
"After many long months of waiting, Martín is now here. He weighs 3,850 kg and he and his mother are both doing fine and are now resting.
"I'm incredibly happy that this moment has finally arrived and that everything has gone well. Without doubt 2014 has begun on the right foot."
Casillas and Carbonero have been dating since 2009, though they only went public with their relationship before the following summer's World Cup in South Africa.
Carbonero famously interviewed her partner after Spain's final triumph over Netherlands, which ended with the Roja captain planting a celebratory kiss on her lips.