Indian national Harpreet Padda, 39, admitted having sex with the child at a house in Greenock, Inverclyde, in 2014.
Padda, who is in the UK illegally, tried to flee after a DNA test but was taken off a flight in London last year.
At the High Court in Glasgow judge Lord Beckett told Padda that he had committed “a despicable crime’.
The judge said Padda’s conduct showed “depravity and wickedness.”
Lord Beckett added: “The public must be protected. The child in this case is extremely vulnerable.
“You deprived her of a normal childhood.”
The court previously heard that the bus driver knew the girl and her family.
The teenager was described as “vulnerable”, but appeared to get on well with Padda.
Prosecutor Angela Gray told the court that the girl’s mother took her to a GP in February last year as she was being sick.
It was discovered the child was 30 weeks pregnant but she refused to say who the father was.
The girl went on to give birth in April 2015. Padda remained silent and his wife had their child a short time later.
When police were called in, Padda gave a DNA sample in late June 2015.
Ms Gray told the court: “A few days after – but before the result of the paternity test – Padda told family in Greenock he was leaving for India.
“He claimed that his mother was ill. The test subsequently confirmed Padda was the father of the baby.”
In July last year, Padda was taken off a flight by police at Heathrow Airport.
The girl later revealed Padda had sex with her once. She was said to be “very distressed” during the police interview.
Original Source – BBC News.