The 31-year-old woman was rushed to hospital in the central Italian city of Rieti after complaining of stomach pains.
After initially thinking the pains were just stomach cramps, It was realised at the hospital she was actually in labour.
The woman, who is originally from El Salvador, named her child Francesco (Francis) after the current Pope, the BBC reports.
Mayor of Rieti, Simone Petrangeli, asked the public and media to respect the woman's privacy after the news caused huge public attention.
A few hours later, she had given birth to a boy.
The woman, who is originally from El Salvador, named her child Francis after the current Pope
The Ansa news agency reports she said: 'I did not know I was pregnant. I only felt a stomach pain.'
The woman lives at the Little Disciples of Jesus convent near Rieti, which manages an old people's home.
Nuns at the convent said they were 'surprised' and local pastor Don Fabrizio Borrello said the new mother planned to take care of the baby.
'I guess she's telling the truth when she says she arrived at the hospital unaware of the pregnancy,' he said.