The unnamed boy from Manchester was said to have been "chuffed to bits" when his 16-year-old girlfriend gave birth to a girl.
The identities of both kids cannot be revealed for legal reasons.
Earlier this year, another 13-year-old boy, Alfie Patten, from Eastbourne, East Sussex, was believed to have become a father when his 15-year-old girlfriend gave birth.
But DNA tests proved that ANOTHER 15-year-old was the real father.
Britain has the highest teenage pregnancy rate in Western Europe, and the fourth highest in the world, after the United States, Hungary and New Zealand. Canada is just behind Britain, in fifth place.
British schoolboy, aged 13, becomes one of world's youngest fathers
By Daily Mail Reporter
04th October 2009
A 13-year-old British schoolboy has become one of the world's youngest fathers (picture posed by model)
A schoolboy aged 13 has become one of Britain's youngest fathers, it was revealed today.
The boy, from Manchester, was 'chuffed to bits' after his 16-year-old girlfriend gave birth to a baby girl this week, according to his family.
'My son is mature for his age and will make a good father. He will make a better dad than most 25-year-old men would,' his father told the Daily Mirror.
The young couple's identity cannot be revealed for legal reasons.
They are said to have been in a relationship for some time, although they did not go to the same school.
His father added: 'He isn't bewildered about about what has happened. He was a bit shocked at first but now he's chuffed to bits.'
Earlier this year another 13-year-old, Alfie Patten, from Eastbourne in East Sussex, was believed to have become a father after his 15-year-old girlfriend conceived.
But DNA tests later showed that another 15-year-old was the father.
Britain has the worst teenage pregnancy rate in Western Europe, with an estimated around 43,000 teenage mothers created in England every year.
This latest case comes after new measures to deal with teenage pregnancies announced by Gordon Brown this week.
He said teenage parents on benefits would be forced to live in 'supervised homes' instead of being given council houses.
'It's time to address a problem that for too long has gone unspoken: the number of children having children,' he declared.
In 2007, there were 42,918 pregnancies among under-18s.
Western European teenage pregnancy rates (birth per 1000 girls aged 15-19)
(United States: 85.8 )